patch 8.0.0327: error message in cmdline window is not translated

Problem:    The E11 error message in the command line window is not
            translated.
Solution:   use _(). (Hirohito Higashi)
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 09102b5..14ef2bd 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -2490,7 +2490,7 @@
 		&& !IS_USER_CMDIDX(ea.cmdidx))
 	{
 	    /* Command not allowed when editing the command line. */
-	    errormsg = get_text_locked_msg();
+	    errormsg = (char_u *)_(get_text_locked_msg());
 	    goto doend;
 	}
 #ifdef FEAT_AUTOCMD