Add submodule hash2

.gitmodules

@@ -838,3 +838,8 @@
 	url = ../mqtt5.git
 	fetchRecurseSubmodules = on-demand
 	branch = .
+[submodule "hash2"]
+	path = libs/hash2
+	url = ../hash2.git
+	fetchRecurseSubmodules = on-demand
+	branch = .

libs/hash2

@@ -0,0 +1 @@
+Subproject commit f2c2f01b9e9efba1ba8a63c6be2b2b4f56e6f1f9