configDB.pm - prevent warning if no 99_files are found in database

git-svn-id: svn://svn.code.sf.net/p/fhem/code/trunk@6124 2b470e98-0d58-463d-a4d8-8e2adae1ed80

fhem/configDB.pm

@@ -464,7 +464,7 @@ sub cfgDB_FW_fileList($$@) {
 
 # read filelist containing 99_ files in database
 sub cfgDB_Read99() {
-  my $ret;
+  my $ret = "";
   my $fhem_dbh = _cfgDB_Connect;
   my $sth = $fhem_dbh->prepare( "SELECT filename FROM fhembinfilesave WHERE filename like '%/99_%.pm' group by filename" );
   $sth->execute();