fix: fix wrongly named environment variables

.env.example

@@ -4,10 +4,10 @@ NETNEUTRALITY_BOT_PREFIX=$
 NETNEUTRALITY_BOT_OWNER=
 NETNEUTRALITY_API_PORT=9000
 
-NETNEUTRALITY_MYSQL_HOST=127.0.0.1
-NETNEUTRALITY_MYSQL_USER=root
-NETNEUTRALITY_MYSQL_PASSWORD=
-NETNEUTRALITY_MYSQL_DATABASE=
-NETNEUTRALITY_MYSQL_PORT=3306
+MYSQL_HOST=127.0.0.1
+MYSQL_USER=root
+MYSQL_PASSWORD=
+MYSQL_DATABASE=
+MYSQL_PORT=3306
 
 NETNEUTRALITY_SENTRY_DSN=