Remove trailing comma after reading strParseIntWithKey

[roginvs]

Original game in function 0x004AFF7C adds 1 to the final result so it automatically skips last comma.

...
      if ( !strcmp_(v10, v5) )
      {
         *v4 += v15 + 1; // <- Here it is
         v18 = 1;
         *v15 = atoi_(v14);
      }
...

This works perfectly fine if there is a trailing comma, but if this part was last part then it is a problem.
This PR moves string pointer only if there is a comma.

This solved issues with Fallout: Nevada random encounters, for example this line

enc_33=Chance:30%,Counter:1,Enc:(1-1) ENC_VgsManiak AMBUSH Player

is now parsed correctly