Update install document

docs/install/debian.html

@@ -145,7 +145,7 @@ <h2>2.3.3. stretch (MariaDB)<a class="headerlink" href="#stretch-mariadb" title=
 % sudo apt update --allow-insecure-repositories
 % sudo apt install -y -V --allow-unauthenticated groonga-keyring
 % sudo apt update
-% sudo apt install -y -V groonga
+% sudo apt install -y -V mariadb-server-10.1-mroonga
 </pre></div>
 </div>
 <p>If you want to use <a class="reference external" href="http://mecab.sourceforge.net/">MeCab</a> as a tokenizer, install groonga-tokenizer-mecab package.</p>