patch 8.1.0052: when mapping to <Nop> times out the next mapping is skipped

Problem:    When a mapping to <Nop> times out the next mapping is skipped.
Solution:   Reset "timedout" when waiting for a character. (Christian
            Brabandt, closes #2921)
diff --git a/src/version.c b/src/version.c
index 5ff56fd..3187cf2 100644
--- a/src/version.c
+++ b/src/version.c
@@ -762,6 +762,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    52,
+/**/
     51,
 /**/
     50,