patch 8.1.0527: using 'shiftwidth' from wrong buffer for folding

Problem:    Using 'shiftwidth' from wrong buffer for folding.
Solution:   Use "buf" instead of "curbuf". (Christian Brabandt)
diff --git a/src/version.c b/src/version.c
index d3a427a..8a64e4a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -793,6 +793,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    527,
+/**/
     526,
 /**/
     525,