patch 8.0.1041: bogus characters when indenting during visual-block append

Problem:    Bogus characters appear when indenting kicks in while doing a
            visual-block append.
Solution:   Recompute when indenting is done. (Christian Brabandt)
diff --git a/src/misc1.c b/src/misc1.c
index abc455e..8ae75e6 100644
--- a/src/misc1.c
+++ b/src/misc1.c
@@ -1589,8 +1589,7 @@
 	    && curbuf->b_p_ai)
     {
 	fixthisline(get_lisp_indent);
-	p = ml_get_curline();
-	ai_col = (colnr_T)(skipwhite(p) - p);
+	ai_col = (colnr_T)getwhitecols_curline();
     }
 #endif
 #ifdef FEAT_CINDENT
@@ -1608,8 +1607,7 @@
 		: KEY_OPEN_BACK, ' ', linewhite(curwin->w_cursor.lnum)))
     {
 	do_c_expr_indent();
-	p = ml_get_curline();
-	ai_col = (colnr_T)(skipwhite(p) - p);
+	ai_col = (colnr_T)getwhitecols_curline();
     }
 #endif
 #if defined(FEAT_VREPLACE) && (defined(FEAT_LISP) || defined(FEAT_CINDENT))