ssml.test: pass -q to the espeak-ng command to prevent it speaking.

tests/ssml.test

@@ -5,7 +5,7 @@ test_ssml() {
 	echo "testing ${INPUT}"
 	cp $(dirname $INPUT)/$(basename ${INPUT%.*}).expected expected.txt
 	ESPEAK_DATA_PATH=`pwd` LD_LIBRARY_PATH=src:${LD_LIBRARY_PATH} \
-		src/espeak-ng -m -v en-US --ipa=2 -f ${INPUT} > actual.txt
+		src/espeak-ng -m -q -v en-US --ipa=2 -f ${INPUT} > actual.txt
 	diff expected.txt actual.txt || exit 1
 }