/jamute mutes too many groups

[awoo-civ]

Steps to reproduce:

1. Create two groups with one of the group's names containing the other, e.g. test123 and test or 134_test_1kd and test.
2. Reinforce a snitch to each group.
3. Execute /jamute test123(whichever group is the one that contains the other one).
4. Have someone not on the groups walk through both snitch fields.

Expected result: Only snitches from test123 are muted.
What actually happens: Snitches from both test123 and test are muted.