Fix Eclipse m2e lifecycle configuration problem for properties-maven-plugin

Adding the properties-maven-plugin with CAMEL-7314 caused problems with Eclipse m2e because the plugin does not provide any lifecycle mapping configuration. As the plugin was added to the Camel build POM (https://github.com/apache/camel/blob/master/pom.xml), the m2e problem is passed down to all sub-projects.

The following error message is displayed in every sub-project in Eclipse:
"Plugin execution not covered by lifecycle configuration: org.codehaus.mojo:properties-maven-plugin:1.0-alpha-2:set-system-properties (execution: default, phase: initialize)"