Fix remove_lines.py script to explicitly read input as cp1252

* The output from sphinx is in cp1252 for CHM builds, which is the only place
  this script is used. Trying to read it as UTF-8 will fail on non-ASCII
  characters.

docs/remove_lines.py

@@ -7,8 +7,13 @@
 # and to remove some extra newlines getting added
 
 import sys
+import codecs
+
 
 def remLines(delim, above, below):
+    WinReader = codecs.getreader('cp1252')
+    sys.stdin = WinReader(sys.stdin.buffer)
+
     buff = []
     line = sys.stdin.readline()
     while line: