Withdrawing an article out for review when another journal posts a call for papers for a special issue that is right on topic?
I would suggest the following steps:


Ask journal #1 if the review process has started. 
If it has not yet started, ask if it can be kept on hold for a few days. 
Meanwhile send a pre-submission inquiry to journal #2.
If journal #2 seems positive about your paper, send a request to withdraw the paper from journal #1. 
Be honest about your reason for withdrawal, and add a word of appreciation for the editor's cooperation and understanding.
Submit to journal #2 once the withdrawal is confirmed.


If the review process has started, it would be advisable to let things be and not withdraw from journal #1. If your paper is rejected from journal #2, you could consider submitting it to another journal rather than going back to journal #1.