Without this change, attempting to start a remote session over VNC would fail
with:
Sep 19 19:54:04 localhost gdm-session-worker: Gdm: GdmSessionWorker: child
'/gnu/store/yy9wq647l37658vgi291a287ll9iw6dc-gdm-42.0/etc/gdm/Xsession' could
not be started: No such file or directory
* gnu/packages/gnome.scm (gdm)[phases]{patch-paths}
<daemon/gdm-session.c>: Patch a reference in so the Xsession script is
correctly found via the GDM_X_SESSION environment variable.
f3e9b069b1