readme: update copyright year

proxycrawl · proxycrawl · commit 294cc808084e · 2021-01-06T14:57:42.000+08:00
diff --git a/README.md b/README.md
@@ -194,4 +194,4 @@ Everyone interacting in the Proxycrawl project’s codebases, issue trackers, ch
 
 ---
 
-Copyright 2020 ProxyCrawl
+Copyright 2021 ProxyCrawl

Original file line number	Diff line number	Diff line change
`@@ -194,4 +194,4 @@ Everyone interacting in the Proxycrawl project’s codebases, issue trackers, ch`
`194`	`194`
`195`	`195`	`---`
`196`	`196`
`197`		`-Copyright 2020 ProxyCrawl`
	`197`	`+Copyright 2021 ProxyCrawl`