fix location of sign script for windows exe files

Author: martinlippert

eclipse-distribution/org.springframework.boot.ide.product.e428/pom.xml

@@ -362,7 +362,7 @@
 
 								<taskdef resource="net/sf/antcontrib/antcontrib.properties" />
 
-								<exec executable="${project.parent.basedir}/scripts/sign-exe.sh" failonerror="true">
+								<exec executable="${project.build.directory}/../../scripts/sign-exe.sh" failonerror="true">
 									<env key="SSH_USER" path="${vm-signing.ssh.user}" />
 									<env key="SSH_KEY" path="${vm-signing.ssh.key}" />
 									<arg value="${project.build.directory}/products/org.springframework.boot.ide.branding.sts4/win32/win32/x86_64/sts-${unqualifiedVersion}.${p2.qualifier}/SpringToolSuite4.exe"/>