runTask: Better quoting

vars/runTask.groovy

@@ -51,7 +51,7 @@ def call(String task, String branch, String repo, String phpversion, String data
             stage("Detect Moodle Version") {
                 steps {
                     moodleversion = sh (
-                        script: 'grep "\$branch" moodle/version.php | sed "s/^[^']*'\\([^']*\\).*\$/\\1/"',
+                        script: 'grep "\$branch" moodle/version.php | sed "s/^[^\']*\'\\([^\']*\\).*\$/\\1/"',
                         returnStdout: true
                     ).trim()
                     runner = "${env.PATHTORUNNER}/${moodleversion}"