Change power of bouncy edges in soccer field as temporary solution for #1367.

Ideally power of bounce should depend on soccer ball weight.

src/physics/physical_object.cpp

@@ -580,7 +580,7 @@ void PhysicalObject::hit(const Material *m, const Vec3 &normal)
     if(isSoccerBall() && m != NULL &&
        m->getCollisionReaction() == Material::PUSH_SOCCER_BALL)
     {
-        m_body->applyCentralImpulse(normal * 1000.0f);
+        m_body->applyCentralImpulse(normal * 100.0f);
     }
 }   // hit