Allow texlive image user to be configured

services/clsi/config/settings.defaults.coffee

@@ -38,7 +38,7 @@ if process.env["COMMAND_RUNNER"]
 			env:
 				HOME: "/tmp"
 			socketPath: "/var/run/docker.sock"
-			user: "tex"
+			user: process.env["TEXLIVE_IMAGE_USER"] or "tex"
 		expireProjectAfterIdleMs: 24 * 60 * 60 * 1000
 		checkProjectsIntervalMs: 10 * 60 * 1000
 	module.exports.path.sandboxedCompilesHostDir = process.env["COMPILES_HOST_DIR"]