Removing polkassembly.network (#304)

all.json

@@ -163,7 +163,6 @@
     "polkapool.live",
     "polkascanner.com",
     "polkasot.js.org",
-    "polkassembly.network",
     "polkastarter.ai",
     "polkastarter.cc",
     "polkastarter.cm",

urlmeta.json

@@ -83,10 +83,6 @@
     "date": "2021-05-05",
     "url": "mywalletsupports.com"
   },
-  {
-    "date": "2021-05-05",
-    "url": "polkassembly.network"
-  },
   {
     "date": "2021-05-05",
     "url": "polkastartor.com"