[evolution-data-server] Correct false runtime warning from camel_folder_info_build()

[Milan Crha <mcrha src gnome org>]

commit 7debd9224dc5fa6e637d62b320482a418404faf8
Author: Milan Crha <mcrha redhat com>
Date:   Thu Jun 14 11:17:20 2018 +0200

    Correct false runtime warning from camel_folder_info_build()
    
    The folders->pdata can be NULL when folders->len is 0, thus do not
    claim the runtime warning when there had been passed no folders.

 src/camel/camel-store.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/camel/camel-store.c b/src/camel/camel-store.c
index 2e530924f..66567e124 100644
--- a/src/camel/camel-store.c
+++ b/src/camel/camel-store.c
@@ -1172,12 +1172,12 @@ camel_folder_info_build (GPtrArray *folders,
        gchar *p, *pname;
        gint i, nlen;
 
-       if (!folders) {
+       if (!folders || !folders->len) {
                g_warn_if_fail (folders != NULL);
                return NULL;
        }
 
-       if (!folders->pdata || !folders->len) {
+       if (!folders->pdata) {
                g_warn_if_fail (folders->pdata != NULL);
                return NULL;
        }