修正apk里面的dex校验信息

filename=os.path.join(outpath,"classes.dex")
newfilename=filename+"_"
with open(filename, 'rb') as f:
fdata = f.read()
shaf=hashlib.sha1()
shaf.update(fdata[32:])
sig=shaf.digest()
newdata=sig+fdata[32:]
chsum=zlib.adler32(newdata)
fdata=fdata[:8]+ struct.pack('i',chsum)+newdata
with open(newfilename, 'wb+') as f:
f.write(data)
os.unlink(filename)
os.rename(newfilename, filename)