[evolution-data-server] camel_imapx_logger_get_prefix: Fix a compiler warning

[Milan Crha <mcrha src gnome org>]

commit 22c1cf4f70bd0708dd8c4aca649be6302d90d319
Author: Milan Crha <mcrha redhat com>
Date:   Mon Feb 24 08:18:29 2014 +0100

    camel_imapx_logger_get_prefix: Fix a compiler warning

 camel/providers/imapx/camel-imapx-logger.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/camel/providers/imapx/camel-imapx-logger.c b/camel/providers/imapx/camel-imapx-logger.c
index e317c52..7938440 100644
--- a/camel/providers/imapx/camel-imapx-logger.c
+++ b/camel/providers/imapx/camel-imapx-logger.c
@@ -210,7 +210,7 @@ camel_imapx_logger_new (gchar prefix)
 gchar
 camel_imapx_logger_get_prefix (CamelIMAPXLogger *logger)
 {
-       g_return_val_if_fail (CAMEL_IS_IMAPX_LOGGER (logger), NULL);
+       g_return_val_if_fail (CAMEL_IS_IMAPX_LOGGER (logger), 0);
 
        return logger->priv->prefix;
 }