never wonder if sun is not sun

By the way an item of the following page suggests the same snipet:
<http://www.faqs.org/faqs/ui-builders/TeleUSE/>
while I am not sure if it was the case.

Change-Id: I9fb0ea0e872cb1697aa953a406527472f0cbccde
Reviewed-on: https://gerrit.libreoffice.org/12330Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>
Tested-by: Markus Mohrhard <markus.mohrhard@googlemail.com>

include/sal/config.h

@@ -86,11 +86,6 @@
 #define SAL_CONFIGFILE( name ) name "rc"
 #endif
 
-#ifdef sun
-#undef sun
-#define sun sun
-#endif
-
 #endif // INCLUDED_SAL_CONFIG_H