UPPERCASE media extensions causing full media files to be read in like nfo files, causing critical failures

[almightiest]

This simple fix will avoid major issues trying to read in full video files like they're NFO files. Note: I tested this with fake names that happened to be a movie, but the same applies to any TV show episode video files, too

Working code:

>>> path1="/mnt/storage3/temp/movies_tests/Goonies 1986 Test Movie/test movie.mkv"
>>> fileExtension = path1.split(".")[-1]
>>> fileExtension
'mkv'
>>> nfoFile = path1.replace('.'+fileExtension, '.nfo')
>>> nfoFile
'/mnt/storage3/temp/movies_tests/Goonies 1986 Test Movie/test movie.nfo'
>>> path1="/mnt/storage3/temp/movies_tests/Goonies 1986 Test Movie/test movie.MKV"
>>> fileExtension = path1.split(".")[-1]
>>> fileExtension
'MKV'
>>> nfoFile = path1.replace('.'+fileExtension, '.nfo')
>>> nfoFile
'/mnt/storage3/temp/movies_tests/Goonies 1986 Test Movie/test movie.nfo'

Old code, not working, as it attempts to read in the MKV file instead of an nfo file:

>>> path1="/mnt/storage3/temp/movies_tests/Goonies 1986 Test Movie/test movie.MKV"
>>> fileExtension = path1.split(".")[-1].lower()
>>> fileExtension
'mkv'
>>> nfoFile = path1.replace('.'+fileExtension, '.nfo')
>>> nfoFile
'/mnt/storage3/temp/movies_tests/Goonies 1986 Test Movie/test movie.MKV'