Update pdfapp.c
Update pdfapp.c

pdfapp_open failed to close the bookmark file after reading.  Now closing.
stacksmith/mupdf1.7a-persist,stacksmith/mupdf1.7a-persist,stacksmith/mupdf1.7a-persist,stacksmith/mupdf1.7a-persist,stacksmith/mupdf1.7a-persist,stacksmith/mupdf1.7a-persist