git hook: fix formatting issue

Author: KotlinIsland

plugin/src/main/kotlin/org/jlleitschuh/gradle/ktlint/GitHook.kt

@@ -53,7 +53,7 @@ private fun postCheck(
             git add ${'$'}file
         fi
     done
-    """.trimIndent()
+    """
 } else {
     ""
 }