patch 8.1.1290: .hgignore and .gitignore are either distributed or in git

Problem:    .hgignore and .gitignore are either distributed or in git, not
            both.
Solution:   Add .gitignore to the distribution and .hgignore to git.  Update
            the entries. (Christian Brabandt, Ken Takata)
diff --git a/src/version.c b/src/version.c
index 99bfb98..676c383 100644
--- a/src/version.c
+++ b/src/version.c
@@ -768,6 +768,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1290,
+/**/
     1289,
 /**/
     1288,