Add reinitializer for upgrades to Contributor

In order to be able to re-initialize the upgraded contract with the
profile manager address, we need a new re-initializer function that is
automatically allowed to only be executed once per contract
implementation version.

Co-authored-by: Michael Bumann <hello@michaelbumann.com>

scripts/upgrade-example.js

@@ -7,7 +7,17 @@ async function main() {
   await kredits.init();
 
   const ContributorV2 = await ethers.getContractFactory("Contributor");
-  const contributor = await upgrades.upgradeProxy(kredits.Contributor.address, ContributorV2);
+  const contributor = await upgrades.upgradeProxy(
+    kredits.Contributor.address,
+    ContributorV2,
+    {
+      call: {
+        fn: "reinitialize",
+        args: [
+          "0xc80d2513277FA04B10403E2D1d7dAa86F931f4d1"
+        ]
+    }
+  });
   console.log("Contributor upgraded");
   console.log(`Contributor address: ${contributor.address}`);
 
@@ -16,4 +26,4 @@ async function main() {
   console.log("DONE!");
 }
 
-main();
+main()