fixed warning about multiline comment

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@10624 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/unix/mimetype.cpp

@@ -299,10 +299,13 @@ static bool IsKnownUnimportantField(const wxString& field);
 //  a) for "brief" format:
 //      <mime type>  <space separated list of extensions>
 //  b) for "expanded" format:
-//      type=<mime type> \ 
-//      desc="<description>" \ 
+//      type=<mime type> BACKSLASH
+//      desc="<description>" BACKSLASH
 //      exts="<comma separated list of extensions>"
 //
+// (where BACKSLASH is a literal '\\' which we can't put here because cpp
+// misinterprets it)
+//
 // We try to autodetect the format of mime.types: if a non-comment line starts
 // with "type=" we assume the second format, otherwise the first one.