Added 'SSH_AGENT_PID' and 'SSH_AUTH_SOCK' to environment whitelist

The ssh-agent environment variables of an ssh-agent that is running
outside the kas build system are not transfered to the bitbake
environment. This causes fetching of private git repositories to
fail.

This patch adds those variables to the environment whitelist.

Signed-off-by: Claudius Heine <ch@denx.de>

kas/libkas.py

@@ -170,6 +170,8 @@ def get_oe_environ(config, build_dir):
         ew = env['BB_ENV_EXTRAWHITE'] + ' '.join(vars)
         env.update({'BB_ENV_EXTRAWHITE': ew})
 
+    vars.extend(['SSH_AGENT_PID', 'SSH_AUTH_SOCK'])
+
     for v in vars:
         if v in os.environ:
             env[v] = os.environ[v]