Hi there @fran.riadigos.flipsi 
Thanks for your question!
We actually have a feature request regarding this, which you can change out here: Limit concurrency on specified (deploy) branches, or on project/app level (only allow X concurrency for app Y) - #16 by viktorbenei
Please make to vote to increase the demand for this feature and thus have it implemented sooner! 
Meanwhile you will also find possible workarounds for this situation in the linked thread 