patch 9.0.1472: ":drop fname" may change the last used tab page

Problem:    ":drop fname" may change the last used tab page.
Solution:   Restore the last used tab page when :drop has changed it.
            (closes #12087)

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1472,
 /**/
     1471,
 /**/