prefs-dialog: Fix the indentation

This allows the previous commit to be easier to review by keeping its
focus on what it actually changes.
3 jobs for wip/aplazas/preferences in 1 minute and 32 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
failed #234646
flatpak

00:01:32

 
  Deploy
skipped #234647
review
skipped #234648
allowed to fail manual
stop_review
 
Name Stage Failure
failed
flatpak Test
[191/256] Compiling C object 'tests/59830eb@@test-ephy-encodings@exe/meson-generated_.._.._src_ephy-type-builtins.c.o'.
[192/256] Compiling C object 'tests/59830eb@@test-ephy-embed-utils@exe/ephy-embed-utils-test.c.o'.
ninja: build stopped: subcommand failed.
Uploading artifacts...
WARNING: epiphany-git.flatpak: no matching files
_build/meson-logs/meson-log.txt: found 1 matching files
WARNING: _build/meson-logs/testlog.txt: no matching files
Uploading artifacts to coordinator... ok id=234646 responseStatus=201 Created token=PwRh1R33
ERROR: Job failed: exit code 1