(LEAD) China urges restraint as N. Korea fires short-range projectiles

(ATTN: ADDS quotes, details in paras 3-5, last 4 paras) BEIJING, March 3 (Yonhap) -- China called for calm and restraint on Thursday as North Korea fired short-range projectiles into the sea, in an apparent show of defiance hours after the U.N. Secu