macos-fortress-dshield: unrecognized option: -replace

[ryandesign (Ryan Carsten Schmidt)]

macos-fortress-dshield fails to activate on Mountain Lion and earlier:

​https://build.macports.org/builders/ports-10.7_x86_64-builder/builds/21526/steps/install-port/logs/stdio

DEBUG: Executing proc-post-org.macports.activate-activate-0
DEBUG: system -W /opt/local/etc/LaunchDaemons/org.macports.macos-fortress-dshield: /usr/bin/plutil -replace ProgramArguments  -xml '<array>  <string>/opt/local/etc/LaunchDaemons/org.macports.macos-fortress-dshield/macos-fortress-dshield.wrapper</string>  <string>start</string>  </array>' org.macports.macos-fortress-dshield.plist
unrecognized option: -replace
plutil: [command_option] [other_options] file...
The file '-' means stdin
Command options are (-lint is the default):
 -help		show this message and exit
 -lint		check the property list files for syntax errors
 -convert fmt	rewrite property list files in format
		fmt is one of: xml1 binary1 json
There are some additional optional arguments:
 -s		be silent on success
 -o path	specify alternate file path name for result;
		the -o option is used with -convert, and is only
		useful with one file argument (last file overwrites);
		the path '-' means stdout
 -e extension	specify alternate extension for converted files
 -r		if writing JSON, output in human-readable form
 --		specifies that all further arguments are file names
Command failed: /usr/bin/plutil -replace ProgramArguments  -xml '<array>  <string>/opt/local/etc/LaunchDaemons/org.macports.macos-fortress-dshield/macos-fortress-dshield.wrapper</string>  <string>start</string>  </array>' org.macports.macos-fortress-dshield.plist
Exit code: 1