Fix quoting of ES_JAVA_OPTS in plugin script

This commit fixes the quoting of ES_JAVA_OPTS in the plugin script on
Windows.

distribution/src/bin/elasticsearch-plugin.bat

@@ -3,7 +3,7 @@
 setlocal enabledelayedexpansion
 setlocal enableextensions
 
-set ES_JAVA_OPTS="--add-opens java.base/sun.security.provider=ALL-UNNAMED %ES_JAVA_OPTS%"
+set ES_JAVA_OPTS=--add-opens java.base/sun.security.provider=ALL-UNNAMED %ES_JAVA_OPTS%
 set ES_MAIN_CLASS=org.elasticsearch.plugins.PluginCli
 set ES_ADDITIONAL_CLASSPATH_DIRECTORIES=lib/tools/plugin-cli
 call "%~dp0elasticsearch-cli.bat" ^