Compile fix

include/openspace/engine/moduleengine.h

@@ -28,6 +28,8 @@
 #include <memory>
 #include <vector>
 
+#include <openspace/util/openspacemodule.h>
+
 namespace ghoul {
 namespace systemcapabilities {
 
@@ -40,8 +42,6 @@ namespace openspace {
 
 namespace scripting { struct LuaLibrary; }
 
-class OpenSpaceModule;
-
 /**
  * The ModuleEngine is the central repository for registering and accessing
  * OpenSpaceModule for the current application run. By initializing (#initialize) the