Fix a grammatical error in the error message.
Fix a grammatical error in the error message.

hemberger/smr,smrealms/smr,hemberger/smr,smrealms/smr,smrealms/smrv2.0,smrealms/smrv2.0,tmaus/smr,gamedevforks/smr,gamedevforks/smr,Curufir/smr,gamedevforks/smr,Curufir/smr,Curufir/smr,hemberger/smr,tmaus/smr,hemberger/smr,smrealms/smrv2.0,smrealms/smr,smrealms/smrv2.0,gamedevforks/smr