patch 8.1.1176: test for dragging a tab is flaky

Problem:    Test for dragging a tab is flaky.
Solution:   Add a brief sleep.
diff --git a/src/testdir/test_termcodes.vim b/src/testdir/test_termcodes.vim
index 42a38d2..ddde7da 100644
--- a/src/testdir/test_termcodes.vim
+++ b/src/testdir/test_termcodes.vim
@@ -325,6 +325,8 @@
         \              'Tab page 2',
         \              '    Xtab1'], a)
 
+    " brief sleep to avoid causing a double-click
+    sleep 20m
     %bwipe!
   endfor
 
diff --git a/src/version.c b/src/version.c
index fb35556..bfb5c59 100644
--- a/src/version.c
+++ b/src/version.c
@@ -772,6 +772,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1176,
+/**/
     1175,
 /**/
     1174,