`mexec-86` integration test fails at Gitpod

[mkarg]

Steps to reproduce:

• Login to Gitpod
• Open https://gitpod.io/#https://github.com/mojohaus/exec-maven-plugin
• In the console run: mvn -Prun-its clean verify
• In the console run: code target/its/mexec-86/target/out.txt

Expected result:

• Build is successful.
• The IDE shows the following file content:

1. System.out line
2. System.err line
3. System.out line
4. System.err line
5. System.out line
Picked up JAVA_TOOL_OPTIONS: -Xmx3189m

Actual result:

• Build fails because MEXEC-86 expects result <5> but was <6>.
• The IDE shows the following file content:

Picked up JAVA_TOOL_OPTIONS: -Xmx3189m
1. System.out line
2. System.err line3. System.out line

4. System.err line
5. System.out line

Apparently the time when java.exe prints its own information about picking up JAVA_TOOLS_OPTIONS is different between Gitpod and all other environments I have tests so far (local Windows 7, Travis CI).

Note: See also #112 which had the same sympoms.