Plugin incompatibility with newer Sonar versions

Version report

2.1.1

Jenkins and plugins versions report:

Jenkins: 2.2.49.2
Sonar: 8.4.1

• What Operating System are you using (both controller, and any agents involved in the problem)?

Linux 3.10.0-1127.19.1.el7.x86_64

Reproduction steps

Setup Publish of coverage using plugin

Results

Expected result:

It should be able to find the master coverage from Sonar

Actual result:

The API used to search for projects is /api/projects/index?search= which is no longer supported by sonar. The plugin fails to find the master coverage from sonar.

{
  "errors": [
    {
      "msg": "Unknown url : /api/projects/index"
    }
  ]
}

Jenkins output

00:23:28  [GitHub PR Status] start
00:23:28  [GitHub PR Status] getting master coverage...
00:23:28  take master coverage from sonar by token
00:23:29  Getting coverage for Git Repo URL: <git repo path> by repo name: <git project name>
00:23:29  Failed to get master coverage for <git repo path>
00:23:29  Exception message 'com.github.terma.jenkins.githubprcoveragestatus.SonarMasterCoverageRepository$SonarProjectRetrievalException: failed to search for sonar project <git project name> - Unexpected character ('<' (code 60)): expected a valid value (JSON String, Number, Array, Object or token 'null', 'true' or 'false')
00:23:29   at [Source: (org.apache.commons.httpclient.AutoCloseInputStream); line: 1, column: 2]'
00:23:29  com.github.terma.jenkins.githubprcoveragestatus.SonarMasterCoverageRepository$SonarProjectRetrievalException: failed to search for sonar project profile-diagnostics - Unexpected character ('<' (code 60)): expected a valid value (JSON String, Number, Array, Object or token 'null', 'true' or 'false')

Start with SonarMasterCoverageRepository and trace the project-search request that uses /api/projects/index?search=. Check the Sonar 8.4.1-compatible search behavior and verify that master coverage can be found without the reported API error.