Fixed improper replacement

PlayerPageExporter was exporting player json file to player%3Duuid.json
but browser parsed that to be file player=uuid.json, leading to the
player page not loading the value

This was because copy-pasting the PageExporter from Server page missed
server= being replaced, while player= was supposed to be replaced.

Fixed by changing server= to player=

Affects issues:
- Fixed #1223

Plan/common/src/main/java/com/djrapitops/plan/delivery/export/PlayerPageExporter.java

@@ -119,7 +119,7 @@ public class PlayerPageExporter extends FileExporter {
     }
 
     private String toJSONResourceName(String resource) {
-        return StringUtils.replaceEach(resource, new String[]{"?", "&", "type=", "server="}, new String[]{"-", "_", "", ""});
+        return StringUtils.replaceEach(resource, new String[]{"?", "&", "type=", "player="}, new String[]{"-", "_", "", ""});
     }
 
     private Response getJSONResponse(String resource) {