patch 8.1.0193: terminal debugger buttons don't always work

Problem:    Terminal debugger buttons don't always work. (Dominique Pelle)
Solution:   Set 'cpo' to its default value.
diff --git a/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim b/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim
index 1bea8f5..4ccbc4c 100644
--- a/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim
+++ b/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim
@@ -56,6 +56,9 @@
   finish
 endif
 
+let s:keepcpo = &cpo
+set cpo&vim
+
 " The command that starts debugging, e.g. ":Termdebug vim".
 " To end type "quit" in the gdb window.
 command -nargs=* -complete=file -bang Termdebug call s:StartDebug(<bang>0, <f-args>)
@@ -943,3 +946,6 @@
     endif
   endfor
 endfunc
+
+let &cpo = s:keepcpo
+unlet s:keepcpo
diff --git a/src/version.c b/src/version.c
index cb2744d..3c9676e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -790,6 +790,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    193,
+/**/
     192,
 /**/
     191,