Update API version to 2.8-SNAPSHOT in pom.xml

In 2.8 the @CanonicalWebUrl annotation never provides a null
URL provider, so remove the @Nullable annotation.

Change-Id: I190ad40e56d91d720ae78942124c03599749107f

pom.xml

diff --git a/pom.xml b/pom.xml
index 68e3e3a..ce5c038 100644
--- a/pom.xml
+++ b/pom.xml
@@ -10,7 +10,7 @@
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <Gerrit-ApiType>PLUGIN</Gerrit-ApiType>
-    <Gerrit-ApiVersion>2.6-SNAPSHOT</Gerrit-ApiVersion>
+    <Gerrit-ApiVersion>2.8-SNAPSHOT</Gerrit-ApiVersion>
   </properties>
 
   <build>

src/main/java/com/googlesource/gerrit/plugins/avatars/gravatar/GravatarAvatarProvider.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/avatars/gravatar/GravatarAvatarProvider.java b/src/main/java/com/googlesource/gerrit/plugins/avatars/gravatar/GravatarAvatarProvider.java
index aca4a47..efc1834 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/avatars/gravatar/GravatarAvatarProvider.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/avatars/gravatar/GravatarAvatarProvider.java
@@ -25,8 +25,6 @@
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 
-import javax.annotation.Nullable;
-
 @Listen
 @Singleton
 public class GravatarAvatarProvider implements AvatarProvider {
@@ -45,8 +43,8 @@
   private final boolean ssl;
 
   @Inject
-  GravatarAvatarProvider(@CanonicalWebUrl @Nullable String canonicalUrl) {
-    ssl = canonicalUrl != null && canonicalUrl.startsWith("https://");
+  GravatarAvatarProvider(@CanonicalWebUrl String canonicalUrl) {
+    ssl = canonicalUrl.startsWith("https://");
   }
 
   @Override