[gnome-builder] html preview: remove dead code

[Sébastien Lafargue <slafargue src gnome org>]

commit caf1c4862781cc7350516a7fe745276c7f32d3dc
Author: Sebastien Lafargue <slafargue gnome org>
Date:   Sun Mar 26 20:27:25 2017 +0200

    html preview: remove dead code

 .../html-preview/html_preview_plugin/__init__.py   |   12 ------------
 1 files changed, 0 insertions(+), 12 deletions(-)
---
diff --git a/plugins/html-preview/html_preview_plugin/__init__.py 
b/plugins/html-preview/html_preview_plugin/__init__.py
index 9d47953..4962266 100644
--- a/plugins/html-preview/html_preview_plugin/__init__.py
+++ b/plugins/html-preview/html_preview_plugin/__init__.py
@@ -94,18 +94,6 @@ builtins.open = new_open
 _ = Ide.gettext
 
 
-def is_sphinx_installed():
-    with open(os.devnull, 'w') as devnull:
-        try:
-            if subprocess.call(['sphinx-build', '--version'],
-                               stdout=devnull, stderr=devnull) == 0:
-                return True
-        except FileNotFoundError:
-            pass
-
-        return False
-
-
 class SphinxState():
     def __init__(self, builddir):
         self.builddir = builddir