Always build RTCIceServer.webidl, since it doesn't rely on WebRTC machinery, and is needed in DummyBinding. Followup for bug 830099.

dom/webidl/WebIDL.mk

@@ -98,6 +98,7 @@ webidl_files = \
   ProcessingInstruction.webidl \
   Rect.webidl \
   RGBColor.webidl \
+  RTCIceServer.webidl \
   Screen.webidl \
   SVGAElement.webidl \
   SVGAltGlyphElement.webidl \
@@ -192,7 +193,6 @@ endif
 ifdef MOZ_WEBRTC
 webidl_files += \
   MediaStreamList.webidl \
-  RTCIceServer.webidl \
   $(NULL)
 endif