Don't draw effect rings w/gravgun equipped.

[StrawWagen]

I get why this was a feature, since the gravgun can pick up, move effects.

But I'm gonna be straight, nobody places, moves effects with the gravgun, it's a weapon you use to "play the game".
If I'm wrong, and someone does use the gravgun to place effects, I feel very confident saying they're vastly outnumbered by the players who use it solely as a weapon.

"cl_draweffectrings 0" does exist, but it's not the "default player experience", it's another, albeit very small, "barrier to entry".

Thanks for considering this very small PR, for what I feel is an equally small oversight.