Change Centerlines of active channels name

[Jdgilby]

Change to 'Active Channels Lines' to stay consistent with how other layers are named.

[KellyMWhitehead]

Changed for 0.9

[joewheaton]

@Jdgilby close if you are satisfied, and reassign to @KellyMWhitehead if they need more work.

@philipbaileynar and @Jdgilby and I missed these in our roundup of 1.0 release tasks. I am assigning this to 1.0, if it is unrealistic, you can move this to 1.1.