prueba
cuando dices editar este fichero:
/themes/tu-plantilla/contact-form.tpl
sirve con introducir el codigo que me aparece en enlazar en el mapa google, es este:
https://maps.google.es/maps/empw?url=https:%2F%2Fmaps.google.es%2Fmaps%3Ff%3Dq%26source%3Ds_q%26hl%3Des%26geocode%3D%26q%3Dsevilla%26aq%3D%26sll%3D37.286243,-5.923498%26sspn%3D0.009373,0.01929%26vpsrc%3D6%26ie%3DUTF8%26hq%3D%26hnear%3DSevilla,%2BAndaluc%25C3%25ADa%26ll%3D37.388096,-5.98233%26spn%3D0.074885,0.154324%26t%3Dm%26z%3D13%26output%3Dembed&hl=es&gl=es
Gracias,