vim-patch:8.2.1166: once mouse move events are enabled getchar() returns them

Problem:    Once mouse move events are enabled getchar() returns them.
Solution:   Ignore K_MOUSEMOVE in getchar(). (closes vim/vim#6424)
ae97b94176

src/nvim/getchar.c

@@ -1322,7 +1322,7 @@ void openscript(
     do {
       update_topline_cursor();          // update cursor position and topline
       normal_cmd(&oa, false);           // execute one command
-      vpeekc();                         // check for end of file
+      (void)vpeekc();                   // check for end of file
     } while (scriptin[oldcurscript] != NULL);
 
     State = save_State;