First run of `next-error` after search selects the *second* error

[fleutot]

After ag-project, the result window has the cursor on the first result

Expected behavior:

• M-g n select the first result and jumps to the row in the relevant buffer.

Actual behavior:

• the second search result is selected and jumped to.

Note: I'd be happy to make a PR about this, but I need a hint as to where the "selection of first result" occurs.

On my machine, the output of ag --version is: 1.0.2 My Emacs version is: 24.5.1 I'm using: Debian stretch