rocketjump fix: clamp velocity instead of hardcode to 0

[LuckyServ]

Let's bring jumping on commons back.

[SirPlease]

Not opposed, but replacing a hardcode with another hardcoded limit doesn't seem optimal.
I'm guessing you reached this value when testing on a 100 tick server?

[LuckyServ]

The number 242.29 is what line 107 output when testing a common jump on a 100 tick server.

I suppose if someone wanted to change the jump velocity in their config this hardcoded value would be annoying. Ideally the value would be the same velocity you get when initiating a normal jump, not sure how to fetch that through the sourcemod api.

The quick and dirty is good enough for my needs on ceda but if you want this to be cleaner feel free to close this request and make the change.