fix error propagation

Author: arnehormann

connection.go

@@ -50,13 +50,16 @@ func (mc *mysqlConn) handleParams() (err error) {
 			for _, charset := range charsets {
 				// ignore errors here - a charset may not exist
 				err = mc.exec("SET NAMES " + charset)
-				if err == nil {
-					var value []byte
-					value, err = mc.getSystemVar("character_set_connection")
-					if string(value) == charset {
-						break
-					}
+				if err != nil {
+					continue
 				}
+				var value []byte
+				value, _ = mc.getSystemVar("character_set_connection")
+				if string(value) == charset {
+					err = nil
+					break
+				}
+				err = errors.New("Could not set charset " + charset)
 			}
 			if err != nil {
 				return