Bump libmongoc to 1.2-beta1

bjori · bjori · commit a556a1ba1899 · 2015-09-03T14:37:08.000-07:00
diff --git a/src/libmongoc b/src/libmongoc
@@ -1 +1 @@
-Subproject commit 8189e90f1ad29fc4a133985452aeec54efd9bb4a
+Subproject commit 3eaf73ed8a88340584a203520ee9ad98fd1b89d3
