[wkrd] Fix dist's project_name

Setuptools extracts/guesses the project name of a source distribution
found in a package index from its download link. This may not exactly
match the project name of the requirement that initially prompted the
search in the package index. More so since PEP 625, which states that
sdists must have normalized - in particular, lowercased - filenames.

This change seems not strictly necessary, but can help avoid needless
inconsistencies.

src/zc/buildout/easy_install.py

@@ -545,7 +545,12 @@ class Installer(object):
         # See https://github.com/buildout/buildout/issues/647
 
         project_name = requirement.project_name
-        dists = [d for d in index[project_name] if d in requirement]
+        dists = [
+          d if d.project_name == project_name else
+          # Fix the dist's project name to match the original requirement
+          d.clone(project_name=project_name)
+          for d in index[project_name] if d in requirement
+        ]
 
         # Workaround by also looking up the name with - instead of .
         # and fixing the name of dists found back to . instead of -.