patch 8.1.0100: terminal debugger: error when setting a watch point

Problem:    Terminal debugger: error when setting a watch point.
Solution:   Don't try defining a sign for a watch point.
diff --git a/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim b/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim
index b6d9ac5..1bea8f5 100644
--- a/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim
+++ b/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim
@@ -863,6 +863,11 @@
 " Handle setting a breakpoint
 " Will update the sign that shows the breakpoint
 func s:HandleNewBreakpoint(msg)
+  if a:msg !~ 'fullname='
+    " a watch does not have a file name
+    return
+  endif
+
   let nr = substitute(a:msg, '.*number="\([0-9]\)*\".*', '\1', '') + 0
   if nr == 0
     return
diff --git a/src/version.c b/src/version.c
index 23b7246..ba3f848 100644
--- a/src/version.c
+++ b/src/version.c
@@ -762,6 +762,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    100,
+/**/
     99,
 /**/
     98,