py3: add missing b'' prefixes in couple of test files

These were missed in the earlier patch and caught by Yuya.

# skip-blame because just b'' prefix

Differential Revision: https://phab.mercurial-scm.org/D4613

tests/test-hgweb-no-path-info.t

@@ -68,7 +68,7 b' should be used from d74fc8dec2b4 onward '
   > 
   > output = stringio()
   > env['QUERY_STRING'] = 'style=raw'
-  > process(hgwebdir({'repo': b'.'}))
+  > process(hgwebdir({b'repo': b'.'}))
   > EOF
   $ $PYTHON request.py
   ---- STATUS

tests/test-hgweb-no-request-uri.t

@@ -74,12 +74,12 b' should be used from d74fc8dec2b4 onward '
   > output = stringio()
   > env['PATH_INFO'] = '/'
   > env['QUERY_STRING'] = 'style=raw'
-  > process(hgwebdir({'repo': b'.'}))
+  > process(hgwebdir({b'repo': b'.'}))
   > 
   > output = stringio()
   > env['PATH_INFO'] = '/repo/file/tip/'
   > env['QUERY_STRING'] = 'style=raw'
-  > process(hgwebdir({'repo': b'.'}))
+  > process(hgwebdir({b'repo': b'.'}))
   > EOF
   $ $PYTHON request.py
   ---- STATUS