Fix small error

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

app/build.gradle

@@ -17,7 +17,7 @@ android {
         applicationId 'com.wireguard.android'
         minSdkVersion 21
         targetSdkVersion 28
-        versionCode 440
+        versionCode 441
         versionName '0.0.20181001'
         buildConfigField 'int', 'MIN_SDK_VERSION', "$minSdkVersion.apiLevel"
     }

app/src/main/java/com/wireguard/config/InetEndpoint.java

@@ -11,6 +11,7 @@ import com.wireguard.android.Application;
 import com.wireguard.android.R;
 
 import java.net.Inet4Address;
+import java.net.Inet6Address;
 import java.net.InetAddress;
 import java.net.URI;
 import java.net.URISyntaxException;
@@ -59,7 +60,7 @@ public class InetEndpoint {
             if (resolvedHost == null)
                 resolvedHost = candidates[0];
         }
-        return String.format(resolvedHost instanceof Inet4Address ?
+        return String.format(resolvedHost instanceof Inet6Address ?
                 "[%s]:%d" : "%s:%d", resolvedHost.getHostAddress(), port);
     }