patch 9.1.0594: Unnecessary redraw when setting 'winfixbuf'

Problem:  Unnecessary redraw when setting 'winfixbuf'.
Solution: Remove P_RWIN flag. (zeertzjq)

closes: #15283

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index 49aeb92..986edc9 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    594,
+/**/
     593,
 /**/
     592,