Fix a mistake in code, which unloads perl modules.

Perl API should be used properly.

git-svn-id: https://znc.svn.sourceforge.net/svnroot/znc/trunk@2274 726aef4b-f618-498e-8847-2d620e286838

modules/modperl.cpp

@@ -127,6 +127,7 @@ public:
 				bSuccess = true;
 				sRetMsg = "Module [" + sModName + "] unloaded";
 			}
+			PEND;
 			DEBUG(__PRETTY_FUNCTION__ << " " << sRetMsg);
 			return HALT;
 		}