Fix #49 using a file with LC_ALL=C as fallback

[comawill]

came across the same problem as in issue #49

noticed that /usr/bin/file crashes, when trying to determine the content type

$ file /tmp/test
/tmp/test: ERROR: line 22: regexec error 17, (illegal byte sequence)

by changing the environment variable LC_ALL to C, it works as expected

LC_ALL=C file /tmp/test
/tmp/test: UTF-8 Unicode text

this PR changes the behavior on running file, by trying to run file again with LC_ALL=C if the first run using LC_ALL=en_US.utf8 failed

[tsdorsey]

Thanks @comawill. I'll merge and release this shortly (48 hours).