CLEANUP: http: remove a useless null check

srv cannot be null in http_perform_server_redirect(), as it's taken
from the stream interface's target which is always valid for a
server-based redirect, and it was already dereferenced above, so in
practice, gcc already removes the test anyway.

Reported-by: Dinko Korunic <dkorunic@reflected.net>
diff --git a/src/proto_http.c b/src/proto_http.c
index 2a88fe0..3d68da8 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -817,8 +817,7 @@
 	http_server_error(s, si, SN_ERR_PRXCOND, SN_FINST_C, 302, &trash);
 
 	/* FIXME: we should increase a counter of redirects per server and per backend. */
-	if (srv)
-		srv_inc_sess_ctr(srv);
+	srv_inc_sess_ctr(srv);
 }
 
 /* Return the error message corresponding to si->err_type. It is assumed