Turn off wget's output in nvm_get_latest()

curl output is turned off by `-s` in the same place, we should unify the
behavior on wget, also, this help removes those wget outputs that can't
fit our coding style tests. cc #1739

nvm.sh

@@ -86,7 +86,7 @@ nvm_get_latest() {
     fi
     NVM_LATEST_URL="$(curl ${CURL_COMPRESSED_FLAG:-} -q -w "%{url_effective}\\n" -L -s -S http://latest.nvm.sh -o /dev/null)"
   elif nvm_has "wget"; then
-    NVM_LATEST_URL="$(wget http://latest.nvm.sh --server-response -O /dev/null 2>&1 | command awk '/^  Location: /{DEST=$2} END{ print DEST }')"
+    NVM_LATEST_URL="$(wget -q http://latest.nvm.sh --server-response -O /dev/null 2>&1 | command awk '/^  Location: /{DEST=$2} END{ print DEST }')"
   else
     nvm_err 'nvm needs curl or wget to proceed.'
     return 1