vcmi: bump serialization version

Saves from this branch are incompatible with generic ones

lib/serializer/CSerializer.h

@@ -14,8 +14,8 @@
 
 VCMI_LIB_NAMESPACE_BEGIN
 
-const ui32 SERIALIZATION_VERSION = 818;
-const ui32 MINIMAL_SERIALIZATION_VERSION = 818;
+const ui32 SERIALIZATION_VERSION = 819;
+const ui32 MINIMAL_SERIALIZATION_VERSION = 819;
 const std::string SAVEGAME_MAGIC = "VCMISVG";
 
 class CHero;