Every time I run "Maven update" on my project, maven forced JRE System Library to the Execution Environment option. Shown below:
How to make M2E allow me to choose the other 2 options?
I had below configuration in my pom.xml in order to override the default J2SE-1.5 version of M2E:
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-compiler-plugin</artifactId>
      <version>3.1</version>
      <configuration>
        <source>1.7</source>
        <target>1.7</target>
      </configuration>
    </plugin>
