installer: Replace boot.iso with installer.iso in .treeinfo as well
installer: Replace boot.iso with installer.iso in .treeinfo as well

Programs like virt-install will look for boot.iso potentially, but we
don't have that, we have an installer.iso.

projectatomic/rpm-ostree-toolbox,maxamillion/rpm-ostree-toolbox,maxamillion/rpm-ostree-toolbox,tlitovsk/rpm-ostree-toolbox,sujitfulse/rpm-ostree-toolbox,markllama/rpm-ostree-toolbox,projectatomic/rpm-ostree-toolbox,giuseppe/rpm-ostree-toolbox,maxamillion/rpm-ostree-toolbox,projectatomic/rpm-ostree-toolbox,maxamillion/rpm-ostree-toolbox,markllama/rpm-ostree-toolbox,giuseppe/rpm-ostree-toolbox,maxamillion/rpm-ostree-toolbox,markllama/rpm-ostree-toolbox,giuseppe/rpm-ostree-toolbox,projectatomic/rpm-ostree-toolbox,tlitovsk/rpm-ostree-toolbox,tlitovsk/rpm-ostree-toolbox,markllama/rpm-ostree-toolbox,sujitfulse/rpm-ostree-toolbox,giuseppe/rpm-ostree-toolbox,giuseppe/rpm-ostree-toolbox,markllama/rpm-ostree-toolbox,sujitfulse/rpm-ostree-toolbox,tlitovsk/rpm-ostree-toolbox,markllama/rpm-ostree-toolbox,maxamillion/rpm-ostree-toolbox,tlitovsk/rpm-ostree-toolbox,giuseppe/rpm-ostree-toolbox,projectatomic/rpm-ostree-toolbox,tlitovsk/rpm-ostree-toolbox,sujitfulse/rpm-ostree-toolbox,sujitfulse/rpm-ostree-toolbox,sujitfulse/rpm-ostree-toolbox