Use a system-wide (uncompressed) GeoIP database instead of trying to
download one at build time.

diff -Naur a/Makefile b/Makefile
--- a/Makefile	2019-03-14 19:32:26.000000000 +0000
+++ b/Makefile	2019-05-11 23:41:19.520479107 +0100
@@ -300,7 +300,7 @@
 	@ $(CP_R) thirdparty/download/*.dll .
 	@ $(CP_R) thirdparty/download/*.dll.config .
 
-linux-dependencies: cli-dependencies geoip-dependencies linux-native-dependencies
+linux-dependencies: cli-dependencies linux-native-dependencies
 
 linux-native-dependencies:
 	@./thirdparty/configure-native-deps.sh
@@ -341,7 +341,6 @@
 	@$(INSTALL_DIR) "$(DATA_INSTALL_DIR)"
 	@$(INSTALL_PROGRAM) $(foreach prog,$(CORE),$($(prog)_TARGET)) "$(DATA_INSTALL_DIR)"
 
-	@$(INSTALL_DATA) "GeoLite2-Country.mmdb.gz" "$(DATA_INSTALL_DIR)/GeoLite2-Country.mmdb.gz"
 	@$(INSTALL_DATA) VERSION "$(DATA_INSTALL_DIR)/VERSION"
 	@$(INSTALL_DATA) AUTHORS "$(DATA_INSTALL_DIR)/AUTHORS"
 	@$(INSTALL_DATA) COPYING "$(DATA_INSTALL_DIR)/COPYING"
diff -Naur a/OpenRA.Game/Network/GeoIP.cs b/OpenRA.Game/Network/GeoIP.cs
--- a/OpenRA.Game/Network/GeoIP.cs	2019-03-14 19:32:26.000000000 +0000
+++ b/OpenRA.Game/Network/GeoIP.cs	2019-05-11 23:40:33.919599297 +0100
@@ -55,9 +55,8 @@
 		{
 			try
 			{
-				using (var fileStream = new FileStream("GeoLite2-Country.mmdb.gz", FileMode.Open, FileAccess.Read))
-					using (var gzipStream = new GZipInputStream(fileStream))
-						database = new Reader(gzipStream);
+				using (var fileStream = new FileStream(Path.Combine(Platform.GameDir, "..", "GeoIP", "GeoLite2-Country.mmdb"), FileMode.Open, FileAccess.Read))
+					database = new Reader(fileStream);
 			}
 			catch (Exception e)
 			{