d48f664440e7bb3ff7a90b6d706a3ac2cfaec95a tests: Fix fs_tests for unknown locales (Daki Carnhof)
Pull request description:
Fix by removing "L" as suggested by meeDamian in
https://github.com/bitcoin/bitcoin/issues/14948#issuecomment-522355441
```
# all in .../bitcoin/src/test
$ uname -m
x86_64
$ export LC_ALL=randomnonexistentlocale
$ ./test_bitcoin
Running 369 test cases...
unknown location(0): fatal error: in "fs_tests/fsbridge_fstream": boost::system::system_error: boost::filesystem::path codecvt to string: error
test/fs_tests.cpp(13): last checkpoint: "fsbridge_fstream" test entry
*** 1 failure is detected in the test module "Bitcoin Core Test Suite"
```
After the patch is applied, the same test under the same conditions runs fine.
```
$ export LC_ALL=randomnonexistentlocale
$ ./test_bitcoin
Running 369 test cases...
*** No errors detected
```
Co-Authored-By: bugs@meedamian.com
ACKs for top commit:
laanwj:
ACK d48f664440e7bb3ff7a90b6d706a3ac2cfaec95a
Tree-SHA512: a9910252b8ce6a05cab5530874549c2999ca2c28e835fc18aa8e5468fb417bd7d245864ec71d9233dd53e02940a9f0691b247430257f27eb0d7c20745d1c846d
