mysql dump: update check for empty data

plugins/localdump/mysql.sh

@@ -93,15 +93,15 @@ function mysql.db.dump(){
             "$_dbname" 2>&1
   fetchrc >/dev/null
 
-  zgrep -iE "(CREATE|INSERT)" "$_dumpfile" >/dev/null
-  typeset -i local _rc2=$?
-  test $_rc2 -ne 0 && echo "ERROR: the dump does not contain any CREATE or INSERT statement."
+  if [ $myrc -eq 0 ]; then
+        zgrep -iE "(CREATE|INSERT)" "$_dumpfile" >/dev/null
+        fetchrc >/dev/null
+        test $myrc -ne 0 && echo "ERROR: no data - the dump doesn't contain any CREATE or INSERT statement."
+  fi
 
-  typeset -i local myrc+=$_rc2
   test $myrc -eq 0 && mysql_COUNT_DUMPS+=1
   test $myrc -eq 0 || mysql_COUNT_ERRORS+=1
 
-  test $myrc -eq 0  
 }
 
 # import [file] --> [database]