patch 8.0.0670: can't use input() in a timer callback

Problem:    Can't use input() in a timer callback. (Cosmin Popescu)
Solution:   Reset vgetc_busy and set timer_busy. (Ozaki Kiichi, closes #1790,
            closes #1129)

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    670,
 /**/
     669,
 /**/