uid_domain: typo a/an backwards incompatible

src/modules/uid_domain/uid_domain_mod.c

@@ -61,7 +61,7 @@ MODULE_VERSION
 
 /*
  * Version of domain table required by the module, increment this value if you
- * change the table in an backwards incompatible way
+ * change the table in a backwards incompatible way
  */
 #define DOMAIN_TABLE_VERSION 2
 #define DOMATTR_TABLE_VERSION 1