[gtk-doc] mkdb: readd space in error message

[Stefan Sauer <stefkost src gnome org>]

commit 2944a07e8e0bbf592a2cbc9ebd3b758155937782
Author: Stefan Sauer <ensonic users sf net>
Date:   Wed Jan 10 19:58:05 2018 +0100

    mkdb: readd space in error message

 gtkdoc/mkdb.py |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/gtkdoc/mkdb.py b/gtkdoc/mkdb.py
index 1b4f4c6..0abdb31 100644
--- a/gtkdoc/mkdb.py
+++ b/gtkdoc/mkdb.py
@@ -2044,8 +2044,10 @@ def ParseStabilityLevel(stability, file, line, message):
     elif sl == 'private':
         stability = "Private"
     else:
-        common.LogWarning(file, line, "%s is %s." % (message, stability) +
-                          "It should be one of these: Stable, Unstable, or Private.")
+        common.LogWarning(file, line,
+                          "%s is %s. It should be one of these: Stable, "
+                          "Unstable, or Private." % (
+                              message, stability))
     return str(stability)