just correct duplicate case with unicode 0x2018 and 0x201C
just correct duplicate case with unicode 0x2018 and 0x201C

jasonzou/marc4j,jasonzou/marc4j,marc4j/marc4j,marc4j/marc4j,kylieloo/473marc4j,Dyrcona/marc4j,kylieloo/473marc4j,kylieloo/473marc4j,Dyrcona/marc4j