Fix typo in mapblock.h

src/mapblock.h

@@ -424,7 +424,7 @@ public:
 	{
 		m_usage_timer += dtime;
 	}
-	u32 getUsageTimer()
+	float getUsageTimer()
 	{
 		return m_usage_timer;
 	}

src/server.cpp

@@ -568,7 +568,7 @@ void Server::AsyncRunStep(bool initial_step)
 		m_env->step(dtime);
 	}
 
-	const float map_timer_and_unload_dtime = 2.92;
+	static const float map_timer_and_unload_dtime = 2.92;
 	if(m_map_timer_and_unload_interval.step(dtime, map_timer_and_unload_dtime))
 	{
 		JMutexAutoLock lock(m_env_mutex);