titan: Use individual thread pool for background GC (#399)

sre-bot · web-flow · commit a3503b22758a · 2019-12-06T10:31:19.000+08:00
diff --git a/librocksdb_sys/libtitan_sys/titan b/librocksdb_sys/libtitan_sys/titan
@@ -1 +1 @@
-Subproject commit 5ab6a37d5e91a40f4218a75f488fdc1f337b92e8
+Subproject commit c12dfdfbeb9b48ac897b05636e9fa03782421f94
