gpick: fix --all with entirely unpushed series


when a series was never pushed, complete_remote_series() will return no
Changes for it. due to a missing check in changify_remote_specs(), this
would lead to an out-of-bounds access.

amends 2ce3a058.

Fixes: QTQAINFRA-6416
Change-Id: I21f63531f574711522c19b80a0baa0902aca9114
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
commita2324d1e7463ccbb1234f944684297d565c2ef68
parent60353d14b04d89ea331d0aa4a69f9b16c695054e
authorOswald Buddenhagen <oswald.buddenhagen@gmx.de>
committerOswald Buddenhagen <oswald.buddenhagen@gmx.de>
commit timeFri, 5 Jul 2024 14:47:15 +0000