Bug#997346: routes: FTBFS: SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 1-2: truncated \uXXXX escape

[s3v]

Dear Maintainer,

Please find attached a trivial patch to fix this issue.

Kind Regards
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -159,7 +159,7 @@
 #latex_use_parts = False
 
 # Additional stuff for the LaTeX preamble.
-latex_preamble = '''
+latex_preamble = r'''
 \usepackage{palatino}
 \definecolor{TitleColor}{rgb}{0.7,0,0}
 \definecolor{InnerLinkColor}{rgb}{0.7,0,0}