net: leaseshelper: Ignore corrupted lease file and rewrite it

Instead of reporting an error and terminating, rewrite the file with
the newly learned info.

src/network/leaseshelper.c

@@ -274,16 +274,16 @@ main(int argc, char **argv)
     if (custom_lease_file_len) {
         if (!(leases_array = virJSONValueFromString(lease_entries))) {
             virReportError(VIR_ERR_INTERNAL_ERROR,
-                           _("invalid json in file: %s"), custom_lease_file);
-            goto cleanup;
-        }
-
+                           _("invalid json in file: %s, rewriting it"),
+                           custom_lease_file);
+        } else {
             if ((size = virJSONValueArraySize(leases_array)) < 0) {
                 virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                                _("couldn't fetch array of leases"));
                 goto cleanup;
             }
         }
+    }
 
     if (!(leases_array_new = virJSONValueNewArray())) {
         virReportError(VIR_ERR_INTERNAL_ERROR, "%s",