patch 8.1.0105: all tab stops are the same

Problem:    All tab stops are the same.
Solution:   Add the variable tabstop feature. (Christian Brabandt,
            closes #2711)
diff --git a/src/version.c b/src/version.c
index e2ccc11..85b6797 100644
--- a/src/version.c
+++ b/src/version.c
@@ -677,6 +677,11 @@
 #else
 	"-user_commands",
 #endif
+#ifdef FEAT_VARTABS
+	"+vartabs",
+#else
+	"-vartabs",
+#endif
 	"+vertsplit",
 #ifdef FEAT_VIRTUALEDIT
 	"+virtualedit",
@@ -779,6 +784,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    105,
+/**/
     104,
 /**/
     103,