Merge branch 'maint'

* maint:
  exec_cmd: remove unused extern

Author: gitster

exec_cmd.c

@@ -3,7 +3,6 @@
 #include "quote.h"
 #define MAX_ARGS	32
 
-extern char **environ;
 static const char *argv_exec_path;
 static const char *argv0_path;