fdo#59728: Fix encoding of .py files as UTF-8 for Python 3

...where it could default to something like CP 1252 instead on Windows, while
keeping backwards compatibility for now with running under Python 2 (where
things apparently worked well with the original code).

Change-Id: I0ddd06771a36e1cd2cc2ce78abd8bd667db7778f
(cherry picked from commit c2445b03)
Reviewed-on: https://gerrit.libreoffice.org/1829Reviewed-by: Michael Stahl <mstahl@redhat.com>
Tested-by: Michael Stahl <mstahl@redhat.com>

pyuno/source/loader/pythonloader.py

@@ -90,7 +90,10 @@ class Loader( XImplementationLoader, XServiceInfo, unohelper.Base ):
                     # read the file
                     filename = unohelper.fileUrlToSystemPath( url )
 
-                    fileHandle = open( filename )
+                    if sys.version >= '3':
+                        fileHandle = open( filename, encoding='utf_8' )
+                    else:
+                        fileHandle = open( filename )
                     src = fileHandle.read().replace("\r","")
                     if not src.endswith( "\n" ):
                         src = src + "\n"