Fix gamepad axis brake behaviour

• It was actually ACCELERATION axis input that was predominantly broken!
  • It was inexplicably slightly under double what it should be (98 instead of the digital value of 50), which meant that although the function would cap it to MAXPLMOVE (50) later, brake analog input struggled to dampen it.
  • Analog brake deceleration also gets a slight buff, from 24 to 25 (previously off from the digital value of 25 due to integer division rounding)
• Remove a pointless, always-true condition for brake handling.
  • Checked whether accel was held down OR whether cmd->forwardmove was less than or equal 0...
  • But further up the same function, cmd was invariably overwritten with a blank I_BaseTiccmd!
  • Therefore, cmd->forwardmove would always equal 0, and the forwardmove subtraction would always occur.

Netsafe due to it happening before inputs are sent over the wire