Clean-up scopes names when reading from config

When customising GitHub OAuth Scopes for login, we need to make sure
that scope names are cleaned up from heading/trailing spaces

Change-Id: I36d3ad968ee8f0b896eaeb9862b6c3fc4e1be944
diff --git a/github-oauth/src/main/java/com/googlesource/gerrit/plugins/github/oauth/GitHubOAuthConfig.java b/github-oauth/src/main/java/com/googlesource/gerrit/plugins/github/oauth/GitHubOAuthConfig.java
index 7d30d19..43d778a 100644
--- a/github-oauth/src/main/java/com/googlesource/gerrit/plugins/github/oauth/GitHubOAuthConfig.java
+++ b/github-oauth/src/main/java/com/googlesource/gerrit/plugins/github/oauth/GitHubOAuthConfig.java
@@ -126,7 +126,7 @@
     if (Strings.emptyToNull(scopesString) != null) {
       String[] scopesStrings = scopesString.split(",");
       for (String scope : scopesStrings) {
-        scopes.add(Enum.valueOf(Scope.class, scope));
+        scopes.add(Enum.valueOf(Scope.class, scope.trim()));
       }
     }