Contribs: update vorbis to 1.3.4

"The primary feature of this release is reduced static data size in
 libvorbisenc."
"No functional changes, but the encoder lib is now a shade over 25% the
 size it was in the 1.3.3 release."

Before: libvorbis_plugin.dll: 1.7MB
After:  libvorbis_plugin.dll: 717kB

contrib/src/vorbis/SHA512SUMS

-6b579517b9caba293ccf88c8806689076ef9c122e5424c704a81a4c461dbc67147dadee1b9a7a678a75c95ab9ed17b98ac1a5da6e2bcd6f7eab19c17616d529f  libvorbis-1.3.3.tar.xz
+f705c7740bec2dc6584ab8f103491a9d462136e3fa76454bde47e2ba04466b896ef066f7f925ad0a44d4c659c962717bc9099b3cecc20f12270d0ad53369ad53  libvorbis-1.3.4.tar.xz

contrib/src/vorbis/rules.mak

 # libvorbis
 
-VORBIS_VERSION := 1.3.3
+VORBIS_VERSION := 1.3.4
 VORBIS_URL := http://downloads.xiph.org/releases/vorbis/libvorbis-$(VORBIS_VERSION).tar.xz
 #VORBIS_URL := $(CONTRIB_VIDEOLAN)/libvorbis-$(VORBIS_VERSION).tar.gz