patch 8.2.2969: subtracting from number option fails when result is zero

Problem:    Subtracting from number option fails when result is zero. (Ingo
            Karkat)
Solution:   Reset the string value when using the numeric value.
            (closes #8351)
diff --git a/src/version.c b/src/version.c
index d031136..055179c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2969,
+/**/
     2968,
 /**/
     2967,