cf-execd breaks exec_command in body executor control

cf-execd unconditionally adds " -Dfrom_cfexecd" to exec_command in body executor control, in cf-execd-runner.c line 185:

<pre>
if (strlen(config->exec_command) > 0)
{
strlcpy(cmd, config->exec_command, CF_BUFSIZE);

if (!strstr(cmd, "-Dfrom_cfexecd"))

{ strcat(cmd, " -Dfrom_cfexecd"); }

}
</pre>

This breaks exec_command that ends with anything other than cf-agent invocation.
Bug was introduced in d4bca14e43a3ca7fd074360564046dcc4be30be9.

Steps to reproduce:

<pre>
body executor control
{
exec_command => "$(sys.workdir)/bin/cf-agent -f failsafe.cf && $(sys.workdir)/bin/cf-agent | grep anything";
}
</pre>

results in:
grep: unknown devices method