This bug is still happening for me in bootsplash 3.1-17.
I tried completely removing bootsplash and reinstalling. Then I tried configuring manually.
$ dpkg --configure bootsplash
Setting up bootsplash (3.1-17) ...
dpkg: error processing bootsplash (--configure):
subprocess post-installation script returned error exit status 10
Errors were encountered while processing:
bootsplash
