Removing n scoreboard points adds them instead

When using the /scoreboard players remove command to remove points from a scoreboard objective, that amount of points is instead added to your score.

For example, if you have a score of 5 and try to remove 1 points, you will end up with a score of 6.

Also, the output from the command incorrectly states that your score has been updated to be the opposite of what it is (5 will be -5, -7 will be 7, etc.).

For example, when you try and remove 1 point from your score of 5, it incorrectly states they your score has been updated to -6, while your score is actually 6. This is consistent with negative scores, meaning that if you were to remove 1 from a player with a score of -5, the output would tell you that their score is now 4, while the players actual score is -4.

Steps to reproduce:

1. Create new world
2. Create new dummy scoreboard objective named "score" (/scoreboard objectives add score dummy)
3. Set your score value to 5 (/scoreboard players set @p score 5)
4. Remove 1 point from your score (/scoreboard players remove @p score 1)