Don't make "replication" magical as a user name, only as a database name, in pg_hba.conf.

Per gripe from Josh Berkus. Backported from commit ed557a373c406bbb2a1843544ebbd856ca4cac47.

src/backend/libpq/hba.c

@@ -490,6 +490,8 @@ check_role(const char *role, Oid roleid, char *param_str)
 				return true;
 		}
 		else if (strcmp(tok, role) == 0 ||
+				 (strcmp(tok, "replication\n") == 0 && 
+				  strcmp(role,"replication") ==0) ||
 				 strcmp(tok, "all\n") == 0)
 			return true;
 	}