libopus: updated to 1.1

Looks like a major update, with better performances for ARM.
diff --git a/jni/libopus/sources/celt/entdec.c b/jni/libopus/sources/celt/entdec.c
index 75e3e45..3c26468 100644
--- a/jni/libopus/sources/celt/entdec.c
+++ b/jni/libopus/sources/celt/entdec.c
@@ -85,7 +85,7 @@
    number=3,
    pages="256--294",
    month=Jul,
-   URL="http://www.stanford.edu/class/ee398/handouts/papers/Moffat98ArithmCoding.pdf"
+   URL="http://www.stanford.edu/class/ee398a/handouts/papers/Moffat98ArithmCoding.pdf"
   }*/
 
 static int ec_read_byte(ec_dec *_this){