Workaround fix for git-commit-plugin

This commit is a workaround until git-commit-id-plugin 2.1.11 is
released. See also issue 124 of that project

Fixes gh-1484

spring-boot-starters/spring-boot-starter-parent/pom.xml

@@ -130,7 +130,8 @@
 						<verbose>true</verbose>
 						<dateFormat>yyyy-MM-dd'T'HH:mm:ssZ</dateFormat>
 						<generateGitPropertiesFile>true</generateGitPropertiesFile>
-						<generateGitPropertiesFilename>${basedir}/target/classes/git.properties</generateGitPropertiesFilename>
+						<!-- Workaround until 2.1.11 is released; should be an absolute path -->
+						<generateGitPropertiesFilename>target/classes/git.properties</generateGitPropertiesFilename>
 					</configuration>
 				</plugin>
 				<!-- Support our own plugin -->