patch 8.1.0173: compiler warning on MS-Windows

Problem:    Compiler warning on MS-Windows.
Solution:   Add type cast. (Mike Williams)

src/libvterm/src/state.c

@@ -268,7 +268,7 @@ static int on_text(const char bytes[], size_t len, void *user)
   if(!npoints)
   {
     vterm_allocator_free(state->vt, codepoints);
-    return eaten;
+    return (int)eaten;
   }
 
   if(state->gsingle_set && npoints)

src/version.c

@@ -789,6 +789,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    173,
 /**/
     172,
 /**/