MDEV-21229 Update wsrep-lib to deal with libstdc++ vector assertion (#1423)

temeo · Jan Lindström · commit 9a6212008999 · 2019-12-09T07:45:40.000+02:00
The assertion was caused by use of operator[] for an empty vector.
The wsrep-lib update changes vector operations which access
the underlying data array to use data() method which is valid
for empty vectors.
diff --git a/wsrep-lib b/wsrep-lib
@@ -1 +1 @@
-Subproject commit c9513bd2e49abbc0941689af1f2f2636a25e253e
+Subproject commit 9b25cebdf11e6da25d83e513a2e4b6db0515abad
