Fikse håndtering av = i titler

[danmichaelo]

Eks. fra isbn 0802713521:

          <datafield tag="245" ind1="1" ind2="0">
            <subfield code="a">E=mc² :</subfield>
            <subfield code="b">a biography of the world's most famous equation</subfield>
            <subfield code="c">David Bodanis</subfield>
          </datafield>

Denne blir vist som E : a biography of the world's most famous equation. Jeg tror koden tror at likhetstegnet er et ISBD-tegn for paralleltittel…