Fix mapy.cz layers

Fixes: #16

manifest.json

@@ -8,7 +8,9 @@
     "128": "icons/icon128.png"
   },
   "permissions": [
-    "https://www.strava.com/*"
+    "declarativeNetRequestWithHostAccess",
+    "https://www.strava.com/*",
+    "https://mapserver.mapy.cz/*"
   ],
   "content_scripts": [
     {
@@ -20,6 +22,15 @@
       ]
     }
   ],
+  "declarative_net_request": {
+    "rule_resources": [
+      {
+        "id": "mapy_cz",
+        "enabled": true,
+        "path": "rules_mapy_cz.json"
+      }
+    ]
+  },
   "web_accessible_resources": [
     "3rd/Leaflet.GoogleMutant.js",
     "3rd/jquery-3.5.1.min.js",

rules_mapy_cz.json

@@ -0,0 +1,24 @@
+[
+  {
+    "id": 1,
+    "priority": 1,
+    "action": {
+      "type": "modifyHeaders",
+      "requestHeaders": [
+        {
+          "header": "referer",
+          "operation": "set",
+          "value": "https://mapy.cz/"
+        },
+        {
+          "header": "origin",
+          "operation": "remove"
+        }
+      ]
+    },
+    "condition": {
+      "initiatorDomains": ["www.strava.com"],
+      "urlFilter": "||mapserver.mapy.cz/*/*-*-*"
+    }
+  }
+]