fix detection of imap folders that don't support modseq, fixes assertion, r/sr=dmose, 455963

mailnews/imap/src/nsImapServerResponseParser.cpp

@@ -1970,7 +1970,7 @@ void nsImapServerResponseParser::resp_text_code()
         AdvanceToNextToken();
       }
     }
-    else if (!PL_strcasecmp(fNextToken, "NOMODSEQ"))
+    else if (!PL_strcasecmp(fNextToken, "NOMODSEQ]"))
     {
       fHighestModSeq = 0;
       fUseModSeq = PR_FALSE;