Remove old citation we don't want people to use

Author: rpep

LICENSE.txt

@@ -22,13 +22,3 @@ SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-
-If you use or extend this software, we encourage you to acknowledge
-this by citing 
-
-Weiwei Wang, Marc-Antonio Bisotti, David Cortes, Hans Fangohr. 
-Fidimag, https://github.com/fangohr/fidimag (2015)
-
-and by informing us by email ([email protected])
-