Error message for max series per label set is incomplete

[alvinlin123]

Describe the bug
The error message returned when max series per label set limit is hit is incomplete.

The format for the error message is "per-labelset series limit of %d exceeded (labelSet: %s, local limit: %d global limit: %d actual)", note that we actually don't have a %d placeholder for actual at the end of the message.

[friedrichg]

@alvinlin123 welcome back! do you want to work on it?

[alvinlin123]

@alvinlin123 welcome back! do you want to work on it?

hahaha thanks for the welcome .... I do intend to find time to work on this ... but first come first serve :)

[alvinlin123]

@friedrichg because you assigned this issue to me, I felt obligated to find time to fix it hahaha .... please review my PR :D