fix compiler error

6 jobs for master in 8 minutes and 24 seconds (queued for 1 second)
Status Job ID Name Coverage
  Setup
passed #22730
setup

00:00:40

 
  Build
passed #22731
build

00:01:16

 
  Test
passed #22732
test

00:01:23

 
  Deploy
passed #22733
deploy

00:02:22

failed #22735
allowed to fail
site

00:00:22

failed #22734
allowed to fail
sonar

00:02:17

 
Name Stage Failure
failed
site Deploy There is an unknown failure, please try again
7600 [INFO] ------------------------------------------------------------------------
7603 [ERROR] Failed to execute goal org.apache.maven.plugins:maven-site-plugin:3.3:site (default-cli) on project psdbg: failed to get report for org.apache.maven.plugins:maven-javadoc-plugin: Failed to execute goal on project matcher: Could not resolve dependencies for project edu.kit.iti.formal.psdbg:matcher:jar:0.1-SNAPSHOT: Could not find artifact edu.kit.iti.formal.psdbg:keydeps:jar:1.0 in central (https://repo.maven.apache.org/maven2) -> [Help 1]
7603 [ERROR]
7604 [ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
7604 [ERROR] Re-run Maven using the -X switch to enable full debug logging.
7604 [ERROR]
7604 [ERROR] For more information about the errors and possible solutions, please read the following articles:
7604 [ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
ERROR: Job failed: exit code 1
failed
sonar Deploy There is an unknown failure, please try again
123282 [INFO] Finished at: 2017-11-11T22:51:37+00:00
123794 [INFO] Final Memory: 63M/484M
123794 [INFO] ------------------------------------------------------------------------
123796 [ERROR] Failed to execute goal org.sonarsource.scanner.maven:sonar-maven-plugin:3.3.0.603:sonar (default-cli) on project psdbg: Unable to execute SonarQube: Fail to get bootstrap index from server: java.io.IOException: subject key, java.security.InvalidKeyException: Invalid RSA public key: DER input, Integer tag error -> [Help 1]
123796 [ERROR]
123796 [ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
123797 [ERROR] Re-run Maven using the -X switch to enable full debug logging.
123797 [ERROR]
123797 [ERROR] For more information about the errors and possible solutions, please read the following articles:
123797 [ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException