fix campaignUrl crash

@@ -23,9 +23,10 @@ import SwiftEventBus
         setBackButton()
         
         webview.navigationDelegate = self
-        let url = URL(string: campaignUrl)!
-        webview.load(URLRequest(url: url))
-        webview.allowsBackForwardNavigationGestures = true
+        if let url = URL(string: campaignUrl) {
+            webview.load(URLRequest(url: url))
+            webview.allowsBackForwardNavigationGestures = true
+        }
 
         webview.configuration.userContentController.add(self, name: "Cosmote")
     }

@@ -1527,14 +1527,14 @@ public class swiftApi {
                 let instanceOfMyApi = MyApi()
                 let campaignInfo = instanceOfMyApi.provideInfoForCampaign()
                 let finalUrl = (item.index_url ?? "")
-                    + "?web_id=" + (campaignInfo?["web_id"] as! String)
-                    + "&app_uuid=" + (campaignInfo?["app_uuid"] as! String)
-                    + "&api_key=" + (campaignInfo?["api_key"] as! String)
+                    + "?web_id=" + (campaignInfo?["web_id"] as? String ?? "")
+                    + "&app_uuid=" + (campaignInfo?["app_uuid"] as? String ?? "")
+                    + "&api_key=" + (campaignInfo?["api_key"] as? String ?? "")
                     + "&session_uuid=" + (item.session_uuid ?? "")
-                    + "&access_token=" + (campaignInfo?["access_token"] as! String)
-                    + "&refresh_token=" + (campaignInfo?["refresh_token"] as! String)
-                    + "&client_id=" + (campaignInfo?["client_id"] as! String)
-                    + "&client_secret=" + (campaignInfo?["client_secret"] as! String)
+                    + "&access_token=" + (campaignInfo?["access_token"] as? String ?? "")
+                    + "&refresh_token=" + (campaignInfo?["refresh_token"] as? String ?? "")
+                    + "&client_id=" + (campaignInfo?["client_id"] as? String ?? "")
+                    + "&client_secret=" + (campaignInfo?["client_secret"] as? String ?? "")
                     + "&Session_ID=" + (campaign._sessionId)
                     + "&businessService=" + (campaign._businessService)
                     + "&offerName=" + (campaign._offerName)
@@ -1569,14 +1569,14 @@ public class swiftApi {
         let instanceOfMyApi = MyApi()
         let campaignInfo = instanceOfMyApi.provideInfoForCampaign()
         let finalUrl = (campaign.index_url ?? "")
-            + "?web_id=" + (campaignInfo?["web_id"] as! String)
-            + "&app_uuid=" + (campaignInfo?["app_uuid"] as! String)
-            + "&api_key=" + (campaignInfo?["api_key"] as! String)
+            + "?web_id=" + (campaignInfo?["web_id"] as? String ?? "")
+            + "&app_uuid=" + (campaignInfo?["app_uuid"] as? String ?? "")
+            + "&api_key=" + (campaignInfo?["api_key"] as? String ?? "")
             + "&session_uuid=" + (campaign.session_uuid ?? "")
-            + "&access_token=" + (campaignInfo?["access_token"] as! String)
-            + "&refresh_token=" + (campaignInfo?["refresh_token"] as! String)
-            + "&client_id=" + (campaignInfo?["client_id"] as! String)
-            + "&client_secret=" + (campaignInfo?["client_secret"] as! String)
+            + "&access_token=" + (campaignInfo?["access_token"] as? String ?? "")
+            + "&refresh_token=" + (campaignInfo?["refresh_token"] as? String ?? "")
+            + "&client_id=" + (campaignInfo?["client_id"] as? String ?? "")
+            + "&client_secret=" + (campaignInfo?["client_secret"] as? String ?? "")
             + "&Session_ID=" + (ccmsCampaign._sessionId)
             + "&businessService=" + (ccmsCampaign._businessService)
             + "&offerName=" + (ccmsCampaign._offerName)