prevent npe if missing contenttype via webdav

            mContentType = "application/octet-stream";

            prop = propSet.get(DavPropertyName.GETCONTENTTYPE);

            if (prop != null) {

                mContentType = (String) prop.getValue();

                String contentType = (String) prop.getValue();

                // dvelasco: some builds of ownCloud server 4.0.x added a trailing ';'

                // to the MIME type ; if looks fixed, but let's be cautious

                if (mContentType.indexOf(";") >= 0) {

                    mContentType = mContentType.substring(0, mContentType.indexOf(";"));

                if (contentType != null) {

                    if (contentType.contains(";")) {

                        mContentType = contentType.substring(0, contentType.indexOf(";"));

                    } else {

                        mContentType = contentType;

                    }

                }

            }