handle invalid log level strings. (FSCORE-69)

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@6604 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/mod/applications/mod_dptools/mod_dptools.c

@@ -635,6 +635,9 @@ SWITCH_STANDARD_APP(log_function)
 		} else {
 			log_str = level;
 		}
+		if (ltype == SWITCH_LOG_INVALID) {
+			ltype = SWITCH_LOG_DEBUG;
+		}
 
 		switch_log_printf(SWITCH_CHANNEL_LOG, ltype, "%s\n", log_str);
 		switch_safe_free(level);