Fixed -unixts option

[Izaron]

Issue #430

This is not a bug - this function is only realised for Teletext files
I radically enabled it for all subtitles
Checked on the .bin file, works well

[cfsmp3]

This is touching a really sensitive thing :-) have you checked it doesn't break anything when -unixts is not used? What about other formats?

[Izaron]

Sorry, I had to explain my actions.
Initially, the global variable utc_refvalue is equals to UINT64_MAX
If we use -unixts, then we change this value - see line https://github.com/CCExtractor/ccextractor/blob/master/src/lib_ccx/params.c#L1943

In fact, the assignment is performed in another piece of code - see line https://github.com/CCExtractor/ccextractor/blob/master/src/lib_ccx/telxcc.c#L1271, but we do not break the program, because opt->noautotimeref= 1 after -unixts and we will not perform the second assignment

In teletext uses its own variable to correct subtitle time - https://github.com/CCExtractor/ccextractor/blob/master/src/lib_ccx/telxcc.c#L127

I've included it for all formats

ADDED: So if we dont use -unixts, anything doesn't break because utc_refvalue is equals to UINT64_MAX. I checked many formats, works well.