patch 9.0.1669: Crash syncing swapfile in new buffer when using sodium crypt

Problem:    Crash syncing swapfile in new buffer when using sodium crypt.
            (James McCoy)
Solution:   Add checks for sodium encryption. (Christian Brabandt,
            closes #12591, closes #12585)
diff --git a/src/version.c b/src/version.c
index d18ecc1..316649f 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1669,
+/**/
     1668,
 /**/
     1667,