remove duplicate nsISocketTransportService.h reference

netwerk/base/public/Makefile.in

@@ -26,7 +26,6 @@ EXPORTS =                         \
         nsICancelable.h           \
         nsIConnectionGroup.h      \
         nsIFileTransportService.h \
-        nsISocketTransportService.h \
         nsINetService.h           \
         nsIProtocolConnection.h   \
         nsIProtocolHandler.h      \