Remove setting net.Conn Deadlines as its not needed anymore (#8269)

This commit fixes a bug introduced in af6c6a2b35.

Setting deadlines in Go results in arbitrary hangs as reported here
https://github.com/golang/go/issues/34385

Fixes https://github.com/minio/minio/issues/7852

cmd/http/accountingconn.go

@@ -0,0 +1,57 @@
+/*
+ * MinIO Cloud Storage, (C) 2017-2019 MinIO, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package http
+
+import (
+	"net"
+)
+
+// AccountingConn - is a generic stream-oriented network connection supporting buffered reader and read/write timeout.
+type AccountingConn struct {
+	net.Conn
+	updateBytesReadFunc    func(int) // function to be called to update bytes read.
+	updateBytesWrittenFunc func(int) // function to be called to update bytes written.
+}
+
+// Read - reads data from the connection using wrapped buffered reader.
+func (c *AccountingConn) Read(b []byte) (n int, err error) {
+	n, err = c.Conn.Read(b)
+	if err == nil && c.updateBytesReadFunc != nil {
+		c.updateBytesReadFunc(n)
+	}
+
+	return n, err
+}
+
+// Write - writes data to the connection.
+func (c *AccountingConn) Write(b []byte) (n int, err error) {
+	n, err = c.Conn.Write(b)
+	if err == nil && c.updateBytesWrittenFunc != nil {
+		c.updateBytesWrittenFunc(n)
+	}
+
+	return n, err
+}
+
+// newAccountingConn - creates a new connection object wrapping net.Conn with deadlines.
+func newAccountingConn(c net.Conn, updateBytesReadFunc, updateBytesWrittenFunc func(int)) *AccountingConn {
+	return &AccountingConn{
+		Conn:                   c,
+		updateBytesReadFunc:    updateBytesReadFunc,
+		updateBytesWrittenFunc: updateBytesWrittenFunc,
+	}
+}