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)
diff --git a/src/version.c b/src/version.c
index d1c6119..d9fef0a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    670,
+/**/
     669,
 /**/
     668,