patch 8.1.1005: test fails because t_F2 is not set

Problem:    Test fails because t_F2 is not set.
Solution:   Add try-catch.
diff --git a/src/testdir/test_registers.vim b/src/testdir/test_registers.vim
index b57555a..ebcc8e1 100644
--- a/src/testdir/test_registers.vim
+++ b/src/testdir/test_registers.vim
@@ -151,12 +151,17 @@
 " characters as an escape sequence.
 func Test_recording_esc_sequence()
   new
-  let save_F2 = &t_F2
+  try
+    let save_F2 = &t_F2
+  catch
+  endtry
   let t_F2 = "\<Esc>OQ"
   call feedkeys("qqiTest\<Esc>", "xt")
   call feedkeys("OQuirk\<Esc>q", "xt")
   call feedkeys("Go\<Esc>@q", "xt")
   call assert_equal(['Quirk', 'Test', 'Quirk', 'Test'], getline(1, 4))
   bwipe!
-  let t_F2 = save_F2
+  if exists('save_F2')
+    let t_F2 = save_F2
+  endif
 endfunc
diff --git a/src/version.c b/src/version.c
index 0b0ab0c..38d5286 100644
--- a/src/version.c
+++ b/src/version.c
@@ -780,6 +780,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1005,
+/**/
     1004,
 /**/
     1003,