Address the following warnings reported by PyLint 2.10.2:
************* Module conf
doc/arm/conf.py:90:10: W1406: The u prefix for strings is no longer necessary in Python >=3.0 (redundant-u-string-prefix)
doc/arm/conf.py:92:12: W1406: The u prefix for strings is no longer necessary in Python >=3.0 (redundant-u-string-prefix)
doc/arm/conf.py:93:9: W1406: The u prefix for strings is no longer necessary in Python >=3.0 (redundant-u-string-prefix)
doc/arm/conf.py:143:31: W1406: The u prefix for strings is no longer necessary in Python >=3.0 (redundant-u-string-prefix)
doc/man/conf.py:33:10: W1406: The u prefix for strings is no longer necessary in Python >=3.0 (redundant-u-string-prefix)
doc/man/conf.py:38:12: W1406: The u prefix for strings is no longer necessary in Python >=3.0 (redundant-u-string-prefix)
doc/man/conf.py:39:9: W1406: The u prefix for strings is no longer necessary in Python >=3.0 (redundant-u-string-prefix)