修复repl_scanner.l中的报错被删除后导致CI用例没过的问题

src/gausskernel/storage/replication/repl_scanner.l

@@ -202,7 +202,13 @@ WAIT				{ return K_WAIT; }
 				}
 
 .				{
-					return T_WORD;
+					if (u_sess->proc_cxt.clientIsSubscription) {
+						return T_WORD;
+					}
+
+					ereport(ERROR,
+							(errcode(ERRCODE_SYNTAX_ERROR),
+							 errmsg("syntax error: unexpected character \"%s\"", yytext)));
 				}
 %%