fix typo in grammar

6 jobs for master in 9 minutes and 16 seconds (queued for 6 minutes and 31 seconds)
Status Job ID Name Coverage
  Setup
passed #24208
setup

00:00:38

 
  Build
passed #24209
build

00:01:03

 
  Test
passed #24210
test

00:01:19

 
  Deploy
passed #24211
deploy

00:02:15

failed #24213
allowed to fail
site

00:00:21

passed #24212
sonar

00:03:37

 
Name Stage Failure
failed
site Deploy There is an unknown failure, please try again
6777 [INFO] ------------------------------------------------------------------------
6781 [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]
6781 [ERROR]
6782 [ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
6782 [ERROR] Re-run Maven using the -X switch to enable full debug logging.
6782 [ERROR]
6782 [ERROR] For more information about the errors and possible solutions, please read the following articles:
6783 [ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
ERROR: Job failed: exit code 1