plproxy - plproxy: geterrcode(): Switch memory context to work around

Log Message:
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geterrcode(): Switch memory context to work around Assert() in CopyErrorData()

Modified Files:
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plproxy/src:
execute.c (r1.17 -> r1.18)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/plproxy/plproxy/src/execute.c?r1=1.17&r2=1.18)