patch 8.1.0761: default value for brief_wait is wrong

Problem:    Default value for brief_wait is wrong.
Solution:   Make the default FALSE. (Ozaki Kiichi, closes #3812, closes #3799)
diff --git a/src/ui.c b/src/ui.c
index ecd5c44..9c08453 100644
--- a/src/ui.c
+++ b/src/ui.c
@@ -222,7 +222,7 @@
     long    remaining = wtime;
     int	    tb_change_cnt = typebuf.tb_change_cnt;
 # ifdef FEAT_JOB_CHANNEL
-    int	    brief_wait = TRUE;
+    int	    brief_wait = FALSE;
 # endif
 
     // When waiting very briefly don't trigger timers.