list: fix when line is empty ; show error

src/var/lib/tyto/program/check.py

@@ -657,7 +657,7 @@ def check_content(post_bottom):
     elif line.startswith('-)'): inlist = False
     if not inlist: continue
     
-    if not line[0] in tyto.markers_lists:
+    if inlist and not line or not line[0] in tyto.markers_lists:
       logs.out("3", 'line %s must start with %s'%(
                    ln, markers_lists
                    ), False