patch 8.1.1217: MS-Windows: no space reserved for font quality name

Problem:    MS-Windows: no space reserved for font quality name.
Solution:   Add quality_name length if present. (Ken Takata, closes #4311)
diff --git a/src/gui_w32.c b/src/gui_w32.c
index 10af357..dbc8d95 100644
--- a/src/gui_w32.c
+++ b/src/gui_w32.c
@@ -3127,7 +3127,8 @@
     quality_name = quality_id2name((int)lf.lfQuality);
 
     res = (char *)alloc((unsigned)(strlen(font_name) + 20
-		    + (charset_name == NULL ? 0 : strlen(charset_name) + 2)));
+		    + (charset_name == NULL ? 0 : strlen(charset_name) + 2)
+		    + (quality_name == NULL ? 0 : strlen(quality_name) + 2)));
     if (res != NULL)
     {
 	p = res;