Merge pull request libgit2#2707 from swisspol/fix_include

Fixed git2.h not including threads.h anymore

Author: carlosmn

include/git2.h

@@ -24,6 +24,7 @@
 #include "git2/diff.h"
 #include "git2/errors.h"
 #include "git2/filter.h"
+#include "git2/global.h"
 #include "git2/graph.h"
 #include "git2/ignore.h"
 #include "git2/index.h"
@@ -56,7 +57,7 @@
 #include "git2/status.h"
 #include "git2/submodule.h"
 #include "git2/tag.h"
-#include "git2/global.h"
+#include "git2/threads.h"
 #include "git2/transport.h"
 #include "git2/tree.h"
 #include "git2/types.h"