This issue is still persist for separate MediaWiki module installer!
So, when downloading Bitnami package for MediaWiki only (146Mb) then it is fixed.
But when downloading module installer from here - https://bitnami.com/stack/wamp/modules#mediawiki (41Mb) then it is reporting the same error -
"There has been an error. Imagemagick is not installed in your stack. This module requires to have Imagemagick installed. The application will exit now."
Which means - when you already have Bitnami bundle installed with some other modules running then it will not work when installing separate MediaWiki module. As you can see MediaWiki module version is the same as in "fixed version" you specified - 1.29.2-0. Maybe that is somehow related to 32/64-bit issue because I was tried to install Bitnami MediaWiki module over Bitnami 64-bit bundle - it fail with mentioned error message.
Also please note - the installer texts are very confusing! For example: "Bitnami MediaWiki Stack admin user creation" - is that a Wiki admin user? Or is that Bitnai stack admin user? If wiki - then I need a different login + password.