Update buildroot to 2021.02.6 (#1607)

* Update buildroot to 2021.02.6

* Renew buildroot-patches

This makes sure that docker-proxy gets bumped to the latest Docker version
as well.

buildroot/support/testing/infra/emulator.py

@@ -77,6 +77,7 @@ class Emulator(object):
         self.qemu = pexpect.spawn(qemu_cmd[0], qemu_cmd[1:],
                                   timeout=5 * self.timeout_multiplier,
                                   encoding='utf-8',
+                                  codec_errors='replace',
                                   env={"QEMU_AUDIO_DRV": "none"})
         # We want only stdout into the log to avoid double echo
         self.qemu.logfile_read = self.logfile
@@ -100,6 +101,8 @@ class Emulator(object):
         if index != 0:
             raise SystemError("Cannot login")
         self.run("dmesg -n 1")
+        # Prevent the shell from wrapping the commands at 80 columns.
+        self.run("stty columns 29999")
 
     # Run the given 'cmd' with a 'timeout' on the target
     # return a tuple (output, exit_code)