fix(pypi): replace all hyphen with underscore before comparing names

lib/datasource/pypi.js

@@ -8,7 +8,7 @@ module.exports = {
 };
 
 function normalizeName(input) {
-  return input.toLowerCase().replace('-', '_');
+  return input.toLowerCase().replace(/-/g, '_');
 }
 
 async function getDependency(purl, config = {}) {