[gimp] plug-ins: allow "html" extension for colorxhtml.

[Jehan <jehanp src gnome org>]

commit 7c6a147ffb5232132bcc095423e24253c8991f78
Author: Jehan <jehan girinstud io>
Date:   Sat Dec 14 14:37:14 2019 +0100

    plug-ins: allow "html" extension for colorxhtml.
    
    There is no reason to limit it to "xhtml" only. Even more, in all
    browsers I tried, the exported page was failing to load with the '.xtml'
    extension, while it loads fine when renamed as '.html'.
    
    Only problem is that now we have 2 plug-ins able to save as html (other
    is file-html-table) and the first in the procedure list (with no
    explicit logics right now) will just shadow the next one. We will have
    to add some generic infrastructure to allow people to choose favorite
    load/export plug-ins, probably in Preferences, next to the raw plug-in
    selection.

 plug-ins/python/colorxhtml.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)
---
diff --git a/plug-ins/python/colorxhtml.py b/plug-ins/python/colorxhtml.py
index ec320c797e..85fe5301ff 100755
--- a/plug-ins/python/colorxhtml.py
+++ b/plug-ins/python/colorxhtml.py
@@ -320,9 +320,7 @@ class ColorXhtml(Gimp.PlugIn):
                                       "(c) GPL V3.0 or later",
                                       "2003")
 
-            # Not sure there is a good reason to set the file extension as xhtml
-            # rather than html. Is it possible to have two plugins use the same extensions?
-            procedure.set_extensions ("xhtml");
+            procedure.set_extensions ("html,xhtml");
 
             procedure.add_argument_from_property(self, "source-file")
             procedure.add_argument_from_property(self, "characters")