config: use en_US as default locale

In theory, the en_US locale is supposed to be aimed at people, while the
C locale is aimed as computers. In theory, one of the remarkable
differences is in sorting:

$ printf '%s\n' \| a \0 \^ \& B c C | LC_COLLATE=C.UTF-8 sort
&
0
B
C
^
a
c
|

The non-sense there is obvious, with "^" sorting in between the letters,
"|" afterwards and sorting of capitals and non-capitals split. The reason
is the ordering is based on the ascii table. In theory, an en_US locale
should be able to provide a sensitive ordering, but what takes care of it
is the libc, and musl does not have it properly implemented. So LC_COLLATE=en_US
will still give the same results. However, that's hopefully going to change
at some point, and there's no harm in setting a sensible locale by default.

Signed-off-by: Pablo Correa Gómez <ablocorrea@hotmail.com>
Reviewed-by: Oliver Smith <ollieparanoid@postmarketos.org>

pmb/config/__init__.py

@@ -113,7 +113,7 @@ defaults = {
     "jobs": str(multiprocessing.cpu_count() + 1),
     "kernel": "stable",
     "keymap": "",
-    "locale": "C.UTF-8",
+    "locale": "en_US.UTF-8",
     "log": "$WORK/log.txt",
     "mirror_alpine": "http://dl-cdn.alpinelinux.org/alpine/",
     # NOTE: mirrors_postmarketos variable type is supposed to be