HPCC-15612 Target hpcc-systems' fork of libcouchbase-cxx

Signed-off-by: rpastrana <rodrigo.pastrana@lexisnexis.com>

.gitmodules

@@ -39,4 +39,4 @@
     url = https://github.com/hpcc-systems/lz4.git
 [submodule "plugins/couchbase/libcouchbase-cxx"]
 	path = plugins/couchbase/libcouchbase-cxx
-	url = https://github.com/couchbaselabs/libcouchbase-cxx.git
+	url = https://github.com/hpcc-systems/libcouchbase-cxx.git