patch 8.1.2226: cannot use system copy/paste in non-xterm terminals

Problem:    Cannot use system copy/paste in non-xterm terminals.
Solution:   Instead of setting 'mouse' to "a" set it to "nvi" in defaults.vim.
diff --git a/src/version.c b/src/version.c
index 3f36958..f5bc809 100644
--- a/src/version.c
+++ b/src/version.c
@@ -742,6 +742,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2226,
+/**/
     2225,
 /**/
     2224,