Improve PLAIN only warning message when using advanced account menu

Monal/Classes/xmpp.m

@@ -2955,7 +2955,7 @@ -(void) handleFeaturesBeforeAuth:(MLXMLNode*) parsedStanza withForceSasl2:(BOOL)
                 //leave that in for translators, we might use it at a later time
                 while(!NSLocalizedString(@"This server isn't additionally hardened against man-in-the-middle attacks on the TLS encryption layer by using authentication methods that are secure against such attacks! This indicates an ongoing attack if the server is supposed to support SASL2 and SCRAM and is harmless otherwise. Use the advanced account creation menu and turn on the PLAIN switch there if you still want to log in to this server.", @""));
 
-                clearPipelineCacheOrReportSevereError(NSLocalizedString(@"This server lacks support for SASL2 and SCRAM, additionally hardening authentication against man-in-the-middle attacks on the TLS encryption layer. Since this server is listed as supporting both at https://github.com/monal-im/SCRAM_PreloadList, an ongoing MITM attack is highly likely! You should try again once you are in a clean networking environment.", @""));
+                clearPipelineCacheOrReportSevereError(NSLocalizedString(@"This server lacks support for SASL2 and SCRAM, additionally hardening authentication against man-in-the-middle attacks on the TLS encryption layer. Since this server is listed as supporting both at https://github.com/monal-im/SCRAM_PreloadList (or you intentionally left the PLAIN switch off when using the advanced account creation menu), an ongoing MITM attack is very likely! Try again once you are in a clean network environment.", @""));
                 return;
             }
         }