Fix Brazil ICAO: SSRS (Barreirinhas) corrected, SNZB (Rancho Sumidor) added

[almireb-sys]

Fixes #215

• SSRS updated to Barreirinhas Lençóis Maranhenses Regional Airport (was incorrectly pointing to Rancho Sumidor)
• SNZB added for Rancho Sumidor Airport (Rio do Oeste, Santa Catarina)

Data sourced from AISWEB/DECEA (official Brazilian aeronautical authority).

[alexander-san]

There is still an error in your PR:
Duplicate "iata" value found: "BRB" in entry "SSRS".

[Jmion]

I think that the SBRR entry should be removed. It seems like some websites falsely report it as Barreirinhas. From the best authoritative source I found 'SBRR' is not a valid airport in Brazil. I would be in favor of dropping the entry for SBRR.

[alexander-san]

I think that the SBRR entry should be removed. It seems like some websites falsely report it as Barreirinhas. From the best authoritative source I found 'SBRR' is not a valid airport in Brazil. I would be in favor of dropping the entry for SBRR.

This is regarding SSRS and SNZB airport. There is no mention of SBRR... @Jmion