Deleted zombie extern variable declaration which was causing a "static declaration follows non-static declaration" gcc compilation error.

git-svn-id: https://svn.code.sf.net/p/rathena/svn/trunk@13103 54d463be-8e91-2dee-dedb-b68131a5f0ec

src/map/script.h

@@ -155,6 +155,4 @@ int add_str(const char* p);
 const char* get_str(int id);
 int script_reload(void);
 
-extern char mapreg_txt[];
-
 #endif /* _SCRIPT_H_ */