Bug 986400 Sync does not start in SeaMonkey 2.28a1 r=Callek

a=bustage fix a=me for CLOSED TREE

This ports Firefox Bug 976002 (Build time flag to enable/disable FxAccounts)

suite/confvars.sh

@@ -28,6 +28,7 @@ MOZ_STATIC_BUILD_UNSUPPORTED=1
 MAIL_MODULE="MODULE(nsMailModule) MODULE(nsImportServiceModule)"
 MOZ_SERVICES_COMMON=1
 MOZ_SERVICES_CRYPTO=1
+MOZ_SERVICES_FXACCOUNTS=1
 MOZ_SERVICES_SYNC=1
 MOZ_URL_CLASSIFIER=1