Update to latest mssqldriver (#7613)

* New driver does not tolerate USE - handle this by closing db and reopening db in the new dbname

vendor/github.com/denisenkom/go-mssqldb/mssql_go110.go

@@ -0,0 +1,47 @@
+// +build go1.10
+
+package mssql
+
+import (
+	"context"
+	"database/sql/driver"
+)
+
+var _ driver.Connector = &Connector{}
+var _ driver.SessionResetter = &Conn{}
+
+func (c *Conn) ResetSession(ctx context.Context) error {
+	if !c.connectionGood {
+		return driver.ErrBadConn
+	}
+	c.resetSession = true
+
+	if c.connector == nil || len(c.connector.SessionInitSQL) == 0 {
+		return nil
+	}
+
+	s, err := c.prepareContext(ctx, c.connector.SessionInitSQL)
+	if err != nil {
+		return driver.ErrBadConn
+	}
+	_, err = s.exec(ctx, nil)
+	if err != nil {
+		return driver.ErrBadConn
+	}
+
+	return nil
+}
+
+// Connect to the server and return a TDS connection.
+func (c *Connector) Connect(ctx context.Context) (driver.Conn, error) {
+	conn, err := c.driver.connect(ctx, c, c.params)
+	if err == nil {
+		err = conn.ResetSession(ctx)
+	}
+	return conn, err
+}
+
+// Driver underlying the Connector.
+func (c *Connector) Driver() driver.Driver {
+	return c.driver
+}