[gnome-control-center] network: Avoid setting a GError if already set

[Bastien Nocera <hadess src gnome org>]

commit 2a6706fe4cae955591a2f160639c1e0b05b86c34
Author: Bastien Nocera <hadess hadess net>
Date:   Tue Jun 14 14:12:26 2016 +0200

    network: Avoid setting a GError if already set
    
    If the wireless security is invalid, don't try to set the GError if the
    ad-hoc mode is invalid as well.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=769230

 .../network/connection-editor/ce-page-security.c   |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/panels/network/connection-editor/ce-page-security.c 
b/panels/network/connection-editor/ce-page-security.c
index 041afcd..9789c75 100644
--- a/panels/network/connection-editor/ce-page-security.c
+++ b/panels/network/connection-editor/ce-page-security.c
@@ -399,7 +399,8 @@ validate (CEPage        *page,
 
                 if (CE_PAGE_SECURITY (page)->adhoc) {
                         if (!wireless_security_adhoc_compatible (sec)) {
-                                g_set_error (error, NM_CONNECTION_ERROR, 
NM_CONNECTION_ERROR_INVALID_SETTING, "Security not compatible with Ad-Hoc mode");
+                                if (valid)
+                                        g_set_error (error, NM_CONNECTION_ERROR, 
NM_CONNECTION_ERROR_INVALID_SETTING, "Security not compatible with Ad-Hoc mode");
                                 valid = FALSE;
                         }
                 }