check fragment state before displaying the next screen

Author: codeismail-waver

rave_android/src/main/java/com/flutterwave/raveandroid/zmmobilemoney/ZmMobileMoneyFragment.java

@@ -267,8 +267,10 @@ public void showToast(String message) {
 
     @Override
     public void showWebPage(String authenticationUrl) {
-        new RaveVerificationUtils(this, ravePayInitializer.isStaging(), ravePayInitializer.getPublicKey(), ravePayInitializer.getTheme())
-                .showWebpageVerificationScreen(authenticationUrl);
+        if(isAdded()){
+            new RaveVerificationUtils(this, ravePayInitializer.isStaging(), ravePayInitializer.getPublicKey(), ravePayInitializer.getTheme())
+                    .showWebpageVerificationScreen(authenticationUrl);
+        }
     }
 
     @Override