Jumping to location from the cmd line doesn't work for current file

[dgaw]

Using the command line to open a file at a particular location doesn't work when the file in question is the currently edited file.

I use this feature for jumping to a location when viewing diffs in tig.

I have a fix for this and will create a PR soon.

Steps to reproduce (in the howl project root):

howl src/Makefile
howl --reuse src/Makefile:8

Expected result:
The cursor is moved to line 8 in the editor.

Actual result:
The cursor remains at line 1.