ALGIERS/MADRID (Reuters) -Algeria has suspended a 20-year-old friendship treaty with Spain that committed the two sides to cooperation in controlling migration flows, escalating a row over Madrid’s stance on Western Sahara. Algerian state media reported the decision without citing any reason, though Algeria had in March withdrawn its ambassador to Spain for consultations because of the Western Sahara dispute. Spanish diplomatic sources confirmed Algeria’s decision, saying the Spanish government regretted the decision and reaffirmed its commitment to the content and principle of the treaty. The…