Updated mp_falldamage 1 with actual Source values.

https://github.com/ValveSoftware/source-sdk-2013/blob/master/mp/src/game/shared/shareddefs.h#L368

// NOTE: The discrete ticks can have quantization error, so these numbers are biased a little to
// make the heights more exact
#define PLAYER_FATAL_FALL_SPEED 922.5f
#define PLAYER_MAX_SAFE_FALL_SPEED 526.5f
#define DAMAGE_FOR_FALL_SPEED 100.0f / ( PLAYER_FATAL_FALL_SPEED - PLAYER_MAX_SAFE_FALL_SPEED )
Merge pull request #555 from HandsomeMatt/falldamage

Updated mp_falldamage 1 with actual Source values.