update sourceUrl

as per: https://github.com/VCVRack/community/issues/397

manifests/TheXOR.json

@@ -3,7 +3,7 @@
   "author": "The XOR",
   "license": "CC0-1.0",
   "manual": "https://github.com/The-XOR/RackPlugins/blob/master/README.md",
-  "sourceUrl": "https://github.com/The-XOR/VCV-Sequencers",
+  "sourceUrl": "https://github.com/The-XOR/RackPlugins",
   "latestVersion": "0.6.0",
   "status": "available"
-}
+}