fixup! easy_install: add slapos.libnetworkcache support

This fixes caching of requirements without canonical versions.

See commit fb785cb3.

src/zc/buildout/easy_install.py

@@ -39,6 +39,7 @@ import tempfile
 import zc.buildout
 import warnings
 from contextlib import closing
+from distutils.version import StrictVersion
 from setuptools.package_index import distros_for_location, URL_SCHEME
 
 WHL_DIST = pkg_resources.EGG_DIST + 1
@@ -480,6 +481,10 @@ class Installer:
                         return max(dists)
                     from .buildout import networkcache_client as nc
                     if nc:
+                        try: # clean up version (e.g. 5.2.0 -> 5.2)
+                            version = str(StrictVersion(version))
+                        except ValueError: # legacy version
+                            pass
                         key = networkcache_key(requirement.key, version)
                         if nc.tryDownload(key):
                             with nc: