Fix - .JSON import of chars > 127 on QT5 problem (leading to ? in text fields)

... on QT5 the conversion of chars > 127 did not work (substituting characters with "?") when loading a .JSON ride file which had such character in their text (e.g. in TAGS)
... by this change the implicite type cast (char to QString) when calling "unprotect" does not take place any more, but the lexer result string is converted directly from 'Local8Bit' to QString to what is has been converted when setting the file-string for lex
... again QT has changed behavior of locale related processing in QT5 (all this worked fine in QT4)