improve error msg

Author: surbhi

src/bitmessagekivy/baseclass/maildetail.py

@@ -109,7 +109,7 @@ def init_ui(self, dt=0):
                 self.assign_mail_details(data)
                 App.get_running_app().set_mail_detail_header()
         except Exception:
-            print('Something went wrong!')
+            print("Error during MailDetail initalization")
 
     def assign_mail_details(self, data):
         """Assign mail details from query result."""