Remove unused imports

Change-Id: Iafbecd99b37d9d88992ed8e3323b37bdff960460
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>

src/main/java/com/googlesource/gerrit/plugins/avatars/external/ExternalUrlAvatarProvider.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/avatars/external/ExternalUrlAvatarProvider.java b/src/main/java/com/googlesource/gerrit/plugins/avatars/external/ExternalUrlAvatarProvider.java
index 902f8d6..50e2b17 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/avatars/external/ExternalUrlAvatarProvider.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/avatars/external/ExternalUrlAvatarProvider.java
@@ -16,8 +16,6 @@
 
 import com.google.gerrit.common.Nullable;
 import com.google.gerrit.extensions.annotations.Listen;
-import com.google.gerrit.reviewdb.client.AccountExternalId;
-import com.google.gerrit.reviewdb.client.AccountExternalId.Key;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.avatar.AvatarProvider;
 import com.google.gerrit.server.config.CanonicalWebUrl;
@@ -31,8 +29,6 @@
 
 import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
 
 @Listen
 @Singleton