patch 9.0.1255: changing 'virtualedit' does not have immediate effect

Problem:    Changing 'virtualedit' does not have immediate effect.
Solution:   Correct how is checked for a changed value. (closes #11878)
diff --git a/src/optionstr.c b/src/optionstr.c
index 29f7f87..0eb9f5b 100644
--- a/src/optionstr.c
+++ b/src/optionstr.c
@@ -2078,7 +2078,7 @@
 	{
 	    if (opt_strings_flags(ve, p_ve_values, flags, TRUE) != OK)
 		errmsg = e_invalid_argument;
-	    else if (STRCMP(p_ve, oldval) != 0)
+	    else if (STRCMP(ve, oldval) != 0)
 	    {
 		// Recompute cursor position in case the new 've' setting
 		// changes something.