searchidx: remove unused sub: next_doc_id

It seems like it was never used

diff --git a/lib/PublicInbox/SearchIdx.pm b/lib/PublicInbox/SearchIdx.pm
index 351450ca8ef1a1dc304a074f590f10eb2375a1a2..87243268a8ad71aa6c85494a5c608fcbdfabd3a2 100644 (file)
--- a/lib/PublicInbox/SearchIdx.pm
+++ b/lib/PublicInbox/SearchIdx.pm
@@ -175,8 +175,6 @@ sub term_generator { # write-only
        $self->{term_generator} = $tg;
 }
 
-sub next_doc_id { $_[0]->{xdb}->get_lastdocid + 1 }
-
 # increments last_thread_id counter
 # returns a 64-bit integer represented as a hex string
 sub next_thread_id {