Update Readme for correct UK country code: GB

Tsunami2056 · web-flow · commit c30229ec7484 · 2023-02-12T17:35:57.000+01:00
It seems the actual geoip2_data_country_iso_code country code for the UK is GB (great britain).
diff --git a/README.md b/README.md
@@ -24,7 +24,7 @@ Follow these steps to enable the maxmind mod:
     ```nginx
     map $geoip2_data_country_iso_code $geo-whitelist {
         default no;
-        UK yes;
+        GB yes;
     }
 
     map $geoip2_data_country_iso_code $geo-blacklist {

Original file line number	Diff line number	Diff line change
`@@ -24,7 +24,7 @@ Follow these steps to enable the maxmind mod:`
`24`	`24`	```nginx
`25`	`25`	`map $geoip2_data_country_iso_code $geo-whitelist {`
`26`	`26`	`default no;`
`27`		`- UK yes;`
	`27`	`+ GB yes;`
`28`	`28`	`}`
`29`	`29`
`30`	`30`	`map $geoip2_data_country_iso_code $geo-blacklist {`