Use subprocess

Signed-off-by: René Jochum <rene@jochum.dev>

docker-entrypoint.py

@@ -7,6 +7,7 @@ import shlex
 import sys
 import glob
 import jinja2
+import subprocess
 
 def jinja_render_file(in_path, data, out_path):
     render_environment = jinja2.Environment(loader=jinja2.FileSystemLoader(os.path.dirname(in_path)))
@@ -42,4 +43,4 @@ os.system("/bin/mkdir -p /data/sieve/global/")
 os.system("/bin/chown mail:mail /data/sieve")
 
 # Run CMD
-os.system(shlex.quote(' '.join(sys.argv[1:])))
+subprocess.call(sys.argv[1:])