Sub: Fix AP_Notify leak flag logic

ArduSub/failsafe.cpp

@@ -292,17 +292,18 @@ void Sub::failsafe_leak_check()
 {
     bool status = leak_detector.get_status();
 
-    AP_Notify::flags.leak_detected = status;
-
     // Do nothing if we are dry, or if leak failsafe action is disabled
     if (status == false || g.failsafe_leak == FS_LEAK_DISABLED) {
         if (failsafe.leak) {
             Log_Write_Error(ERROR_SUBSYSTEM_FAILSAFE_LEAK, ERROR_CODE_FAILSAFE_RESOLVED);
         }
+        AP_Notify::flags.leak_detected = false;
         failsafe.leak = false;
         return;
     }
 
+    AP_Notify::flags.leak_detected = status;
+
     uint32_t tnow = AP_HAL::millis();
 
     // We have a leak