Add backslash in lily58 domnantas keymap

[domnantas]

Minor update to personal keymap

Description

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout/userspace (addition or update)
• Documentation

Issues Fixed or Closed by This PR

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

[noroadsleft]

Hm, this keymap doesn't seem to compile:

Making lily58/rev1 with keymap domnantas

avr-gcc.exe (GCC) 8.4.0
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Compiling: keyboards/lily58/keymaps/domnantas/keymap.c                                             keyboards/lily58/keymaps/domnantas/keymap.c:67:13: error: conflicting types for 'is_keyboard_left'
 const bool *is_keyboard_left(void);
             ^~~~~~~~~~~~~~~~
In file included from tmk_core/common/action.h:22,
                 from quantum/keymap.h:22,
                 from quantum/quantum.h:30,
                 from keyboards/lily58/rev1/rev1.h:5,
                 from keyboards/lily58/lily58.h:4,
                 from keyboards/lily58/keymaps/domnantas/keymap.c:17:
tmk_core/common/keyboard.h:66:6: note: previous declaration of 'is_keyboard_left' was here
 bool is_keyboard_left(void);
      ^~~~~~~~~~~~~~~~
 [ERRORS]
 |
 |
 |
make[1]: *** [tmk_core/rules.mk:417: .build/obj_lily58_rev1_domnantas/keyboards/lily58/keymaps/domnantas/keymap.o] Error 1
Make finished with errors
make: *** [Makefile:523: lily58/rev1:domnantas] Error 1

Tried this source branch and qmk:master.

[stale]

Thank you for your contribution!
This pull request has been automatically marked as stale because it has not had activity in the last 45 days. It will be closed in 30 days if no further activity occurs. Please feel free to give a status update now, or re-open when it's ready.
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[fauxpark]

Thanks!