Fix unused ICS_MAX warning

extern/oics/ICSInputControlSystem.cpp

@@ -28,6 +28,8 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 namespace ICS
 {
+	const float ICS_MAX = std::numeric_limits<float>::max();
+
 	InputControlSystem::InputControlSystem(std::string file, bool active
 		, DetectingBindingListener* detectingBindingListener
 		, InputControlSystemLog* log, size_t channelCount)

extern/oics/ICSInputControlSystem.h

@@ -236,7 +236,7 @@ namespace ICS
 
 	};
 
-	static const float ICS_MAX = std::numeric_limits<float>::max();
+	extern const float ICS_MAX;
 }