Replace CC-BY-SA textures.

Replace textures that aren't GPL license-compatible.

From https://github.com/gilbertohasnofb/new-regional-textures
commit 581fb2795a4e068f807ad8c45558eddcf4c0b69c

As requested by Gilberto AGOSTINHO.

Thanks

@@ -885,24 +885,20 @@ gratefully acknowledged:
    satellite images of the Brazilian cerrado: 
    http://downloads.ibge.gov.br/downloads_geociencias.htm
 
- - Diogo Sergio for the image of the caatinga trees: 
-   http://commons.wikimedia.org/wiki/File:Caatinga_Xiquexique_pedras_01.JPG
-
  - Maria Hsu for the image of a caatinga tree: 
    https://www.flickr.com/photos/14323530@N05/2150992479/
 
- - Leonardo "Leguas" Carvalho for the image of the Ipe-Amarelo tree: 
-   http://pt.wikipedia.org/wiki/Ficheiro:Ipe_detail.jpg
-
- - Spoladore for the image of the Lixeira tree: 
-   http://pt.wikipedia.org/wiki/Cajueiro-bravo-do-campo#/media/File:Lixeira_do_cerrado_de_Mato_Grosso.JPG
+ - Maria Hsu for the image Caatinga - Sertão nordestino.jpg: 
+   https://commons.wikimedia.org/wiki/File:Caatinga_-_Sert%C3%A3o_nordestino.jpg
 
  - Otávio Nogueira for the image of a cerrado tree: 
    https://www.flickr.com/photos/55953988@N00/3896942038
 
- - P199 for the image of Las Piñas City, the Philippines: 
-   http://commons.wikimedia.org/wiki/File:Las_Pinas_City.jpg
+ - Leandro Neumann Ciuffo for the image Cerrado sul-mato-grossense (5801201223).jpg: 
+   https://commons.wikimedia.org/wiki/File:Cerrado_sul-mato-grossense_%285801201223%29.jpg
 
+ - Guilherme Jofili for the image Basta uma chuvinha e o sertao colore!: 
+   https://www.flickr.com/photos/gjofili/8220416529/
 
 NOTE:
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