Increases the loglevel while failed to delete a collection

One of the reasons that sdbm failed to delete a key is the fact that it may
already been excluded). The error logs are not clear regarding that. Check
if the key exists prior to delete will generate unecessary computation. This
commit increases the loglevel of the error message and makes it acts like the
operation was successfully accomplished.

apache2/persist_dbm.c

@@ -217,14 +217,13 @@ static apr_table_t *collection_retrieve_ex(apr_sdbm_t *existing_dbm, modsec_rec
 
         rc = apr_sdbm_delete(dbm, key);
         if (rc != APR_SUCCESS) {
-            msr_log(msr, 1, "collection_retrieve_ex: Failed deleting collection (name \"%s\", "
-                "key \"%s\"): %s", log_escape(msr->mp, col_name),
+            msr_log(msr, 9, "collection_retrieve_ex: Failed deleting collection (name \"%s\", "
+                "key \"%s\"): %s (It may already have been excluded).", log_escape(msr->mp, col_name),
                 log_escape_ex(msr->mp, col_key, col_key_len), get_apr_error(msr->mp, rc));
             msr->msc_sdbm_delete_error = 1;
-            goto cleanup;
+            /*goto cleanup;*/
         }
 
-
         if (existing_dbm == NULL) {
             apr_sdbm_close(dbm);
             dbm = NULL;