Prevent empty commits, closes #527

Author: fabapp2

components/sbm-core/src/main/java/org/springframework/sbm/engine/git/GitSupport.java

@@ -252,7 +252,7 @@ public void commitWhenGitAvailable(ProjectContext context, String appliedRecipeN
                 .map(r -> context.getProjectRootDirectory().relativize(Path.of(r)).toString())
                 .collect(Collectors.toList());
 
-        if (sbmApplicationProperties.isGitSupportEnabled()) {
+        if (sbmApplicationProperties.isGitSupportEnabled() && (!modifiedResources.isEmpty() || !deletedResources.isEmpty())) {
             File repoDir = context.getProjectRootDirectory().toFile();
             if (repoExists(repoDir)) {
                 String commitMessage = "SBM: applied recipe '" + appliedRecipeName + "'";