build: fix default values in startup script for docker

startup.sh

@@ -1,9 +1,5 @@
 #!/bin/sh
 
-prop() {
-    grep "${1}" bot.properties | cut -d'=' -f2
-}
-
 _term() {
   echo "Caught SIGTERM/SIGINT signal, graceful shutdown of bot.."
   if [ -z "$pid" ]; then
@@ -29,11 +25,11 @@ if [ -z $API_PORT ]; then
 fi
 
 if [ -z $MYSQL_HOST ]; then
-  MYSQL_HOST="$(prop 'MYSQL_HOST')"
+  MYSQL_HOST="localhost"
 fi
 
 if [ -z $MYSQL_PORT ]; then
-  MYSQL_PORT=$(prop 'MYSQL_PORT')
+  MYSQL_PORT=3306
 fi
 
 echo "Waiting 10 seconds for database to start.."