Bug 1394868 Fix include casing in VTableBuilder.h to fix MinGW build r=aklotz

MozReview-Commit-ID: 8YHKyOOd7S5

--HG--
extra : rebase_source : d1ae0def3418235632b2ac8d671d4e8d3f6fa2b4

ipc/mscom/VTableBuilder.h

@@ -8,7 +8,7 @@
 #define mozilla_mscom_VTableBuilder_h
 
 #include <stdint.h>
-#include <Unknwn.h>
+#include <unknwn.h>
 
 #if defined(__cplusplus)
 extern "C" {