fixed import function of 1.2 data service

Author: jricher

openid-connect-server/src/main/java/org/mitre/openid/connect/service/impl/MITREidDataService_1_2.java

@@ -1033,7 +1033,7 @@ private void readClients(JsonReader reader) throws IOException {
 } else if (name.equals("initiateLoginUri")) {
 client.setInitiateLoginUri(reader.nextString());
 } else if (name.equals("postLogoutRedirectUri")) {
-HashSet<String> postLogoutUris = Sets.newHashSet(reader.nextString());
+Set<String> postLogoutUris = readSet(reader);
 client.setPostLogoutRedirectUris(postLogoutUris);
 } else if (name.equals("requestUris")) {
 Set<String> requestUris = readSet(reader);