patch 8.1.0212: preferred cursor column not set in interfaces

Problem:    Preferred cursor column not set in interfaces.
Solution:   Set w_set_curswant when setting the cursor. (David Hotham,
            closes #3060)
diff --git a/src/if_tcl.c b/src/if_tcl.c
index 9ecabf8..2289365 100644
--- a/src/if_tcl.c
+++ b/src/if_tcl.c
@@ -1091,6 +1091,7 @@
 	    /* TODO: should check column */
 	    win->w_cursor.lnum = val1;
 	    win->w_cursor.col = col2vim(val2);
+	    win->w_set_curswant = TRUE;
 	    flags |= FL_UPDATE_SCREEN;
 	    break;