Remove incorrect rendering of separator field chars

Unconditionally rendering the separator is wrong, for example, for the
TOC field it causes an extra space at the start of the first entry. In
any case, many common fields are webHidden, so they dont display anyway.

src/calibre/ebooks/docx/to_html.py

@@ -440,8 +440,6 @@ class Convert(object):
                     l.set('class', 'noteref')
                     text.add_elem(l)
                     ans.append(text.elem)
-            elif is_tag(child, 'w:fldChar') and get(child, 'w:fldCharType') == 'separate':
-                text.buf.append('\xa0')
         if text.buf:
             setattr(text.elem, text.attr, ''.join(text.buf))