[geary/wip/714104-refine-account-dialog] Fix credentials check in ServiceInformation.equal_to

[Michael Gratton <mjog src gnome org>]

commit a4768bce73b91910c2802cce5a3eea53cb120b45
Author: Michael Gratton <mike vee net>
Date:   Thu Dec 20 19:30:29 2018 +1100

    Fix credentials check in ServiceInformation.equal_to

 src/engine/api/geary-service-information.vala | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/src/engine/api/geary-service-information.vala b/src/engine/api/geary-service-information.vala
index 1453b95e..cd1531cf 100644
--- a/src/engine/api/geary-service-information.vala
+++ b/src/engine/api/geary-service-information.vala
@@ -186,8 +186,9 @@ public class Geary.ServiceInformation : GLib.Object {
             (this.host == other.host &&
              this.port == other.port &&
              this.transport_security == other.transport_security &&
-             (this.credentials == null && other.credentials == null ||
-              this.credentials != null && this.credentials.equal_to(other.credentials)) &&
+             ((this.credentials == null && other.credentials == null) ||
+              (this.credentials != null && other.credentials != null &&
+               this.credentials.equal_to(other.credentials))) &&
              this.credentials_requirement == other.credentials_requirement &&
              this.remember_password == other.remember_password)
         );