Demodocs: fix compiling warning
Demodocs: fix compiling warning

snide/sphinx_rtd_theme,mitya57/sphinx_rtd_theme,snide/sphinx_rtd_theme,mitya57/sphinx_rtd_theme,mitya57/sphinx_rtd_theme,snide/sphinx_rtd_theme,snide/sphinx_rtd_theme,mitya57/sphinx_rtd_theme