WT1.1.2e error fixes

lib/service/firebase_api.dart

@@ -72,14 +72,13 @@ class FirebaseApi {
         throw Exception("Password too short");
       } else if (e.code == 'email-already-in-use') {
         print('The account already exists for that email.');
-        throw Exception("Customer exists");
         rc = REGISTER_EMAIL_IN_USE;
+        throw Exception("Customer exists");
       }
     } catch (e) {
       print(e);
       throw Exception(e.toString());
     }
-
     return rc;
   }