Steps to reproduce:
1. send several custom parameters via LTI (for example when using the default settings of http://lti.tools/saltire/tc)
2. Opencast LTI adds the custom params to the query string of the requested tool, but does not guarantee the order
The series tool only looks at the first item in the query string so if another custom param is first then the series ID is not added to the search request
The series tool should use the provided series ID in it's search request whatever order params appear in the query string.
Workaround (if any):