Use sphinx-svg2pdfconverter as SVG handler instead.

docs/conf.py

diff --git a/docs/conf.py b/docs/conf.py
index d03c8ae..14d18bf 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -197,7 +197,5 @@
                  r'\DeclareUnicodeCharacter{F057}{\ensuremath{\otimes}}'
 }
 
-image_converter_args=["-quiet"]
-
 def setup(app):
     app.add_css_file('GF_theme.css')

docs/requirements.txt

diff --git a/docs/requirements.txt b/docs/requirements.txt
index 1a35547..187e84b 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -4,4 +4,5 @@
 sphinx
 sphinx-autobuild
 sphinxcontrib-wavedrom
+sphinxcontrib-svg2pdfconverter