Fix problem with GRANT not recognizing backslash

If database grant has backslash in database name (for example: example\_dev), then puppet will try to apply same resource every run because MySQL reports that table name with double backslash (for example: example\\_dev). By global replace of double backslash with single one, this issue is fixed.
Merge pull request #540 from jsosic/patch-1

Fix problem with GRANT not recognizing backslash