Fixing MIDL header file pattern for Visual Studio

_i.h given in 799ee6b7#gitext://gotocommit/799ee6b79e1d32f49ded6683b5364017fd4ee0a5 is wrong

VisualStudio.gitignore

@@ -59,7 +59,7 @@ StyleCopReport.xml
 # Files built by Visual Studio
 *_i.c
 *_p.c
-*_i.h
+*_h.h
 *.ilk
 *.meta
 *.obj