[Releng] Remove diffmerge.
It has broken absolute URIs to its subprojects.
diff --git a/setups/org.eclipse.projects.setup b/setups/org.eclipse.projects.setup
index 7fb0411..e09728e 100644
--- a/setups/org.eclipse.projects.setup
+++ b/setups/org.eclipse.projects.setup
@@ -968,7 +968,6 @@
<project href="https://git.eclipse.org/c/egit/egit.git/plain/tools/oomph/EGit.setup#/"/>
<project href="http://git.eclipse.org/c/emf/org.eclipse.emf.git/plain/releng/org.eclipse.emf.releng/EMF.setup#/"/>
<project href="interim/EMFCompare.setup#/"/>
- <project href="https://raw.githubusercontent.com/eclipse/org.eclipse.emf.diffmerge.core/master/releng/org.eclipse.emf.diffmerge.releng/setup/EMFDiffMerge.setup#/"/>
<project href="http://git.eclipse.org/c/emf-parsley/org.eclipse.emf-parsley.git/plain/devtools/org.eclipse.emf.parsley.oomph/EMFParsley.setup#/"/>
<project href="interim/EPPPackages.setup#/"/>
<project href="https://git.eclipse.org/c/epsilon/org.eclipse.epsilon.git/plain/releng/org.eclipse.epsilon.releng/epsilonDev.setup#/"/>
