do not throw exception when config file not exist

Signed-off-by: Jing Quanqi <jqq@dream.cn>

Author: dodocat

build.gradle

@@ -4,7 +4,7 @@ apply plugin: 'signing'
 
 sourceCompatibility = 1.6
 group = 'org.quanqi'
-version = "0.1.4-SNAPSHOT"
+version = "0.1.4"
 
 repositories {
     mavenCentral()

src/main/groovy/org/quanqi/gradle/signing/AndroidApplicationSigning.groovy

@@ -29,23 +29,20 @@ class AndroidApplicationSigning implements Plugin<Project> {
     void apply(Project project) {
         project.extensions.create("key_store", AndroidApplicationSigningExtension.class)
 
-        if (project.hasProperty("${project.key_store.store}")) {
-
-        }
-
         if (!project.plugins.findPlugin("com.android.application") && !project.plugins.findPlugin("android")) {
             throw new ProjectConfigurationException("The android plugin must be applied to the project", null)
         }
 
-        def keysXmlFile = null
+        def keysXmlFile
         if (project.hasProperty(KEY_ANDROID_KEY_STORE_CONFIG)) {
             keysXmlFile = new File(KEY_ANDROID_KEY_STORE_CONFIG)
         } else {
             keysXmlFile = new File(System.getProperty('user.home'), '.android_key_store.xml')
         }
 
         if (!keysXmlFile.exists()) {
-            println("signing configration not")
+            println("Signing config file not exist.")
+            return
         }
 
         def slurper = new XmlSlurper();