banner.py: make default bool values strings

If the options are not specified in the config file, then the values are taken from the defaults dict. Since strtobool is used, the values are expected to be strings.

Fixes SecurityCentral#4.

classification_banner/banner.py

@@ -234,14 +234,14 @@ def configure(self):
         defaults["font"] = "liberation-sans"
         defaults["size"] = "small"
         defaults["weight"] = "bold"
-        defaults["show_top"] = True
-        defaults["show_bottom"] = True
+        defaults["show_top"] = "True"
+        defaults["show_bottom"] = "True"
         defaults["horizontal_resolution"] = 0
         defaults["vertical_resolution"] = 0
-        defaults["sys_info"] = False
+        defaults["sys_info"] = "False"
         defaults["opacity"] = 0.75
-        defaults["esc"] = True
-        defaults["spanning"] = False
+        defaults["esc"] = "True"
+        defaults["spanning"] = "False"
 
         conf = SafeConfigParser()
         conf.read(CONF_FILE)