skip leading -t expression whitespace HEAD master

Seems like there shouldn't be terrible consequences, the parse error
without it is hard to understand and took me a while to debug when I was
trying to use lr in a shell script like

    lr -t '
        -- nicely-formatted multiline expression goes here
    '

Message-ID: <2MWMP6HZDV8FW.2JYP28P850115@silby.fyi>

1 files changed, 1 insertions, 0 deletions

diff --git a/lr.c b/lr.c
index 17236c5..049b535 100644
--- a/lr.c
+++ b/lr.c
@@ -914,6 +914,7 @@ static struct expr *
 parse_expr(const char *s)
 {
 	pos = (char *)s;
+	ws();
 	struct expr *e = parse_cond();
 	if (*pos)
 		parse_error("trailing garbage at '%.15s'", pos);