Bump dav4jvm from 2.1.2 to 2.1.3

Bumps dav4jvm from 2.1.2 to 2.1.3.

---
updated-dependencies:
- dependency-name: com.gitlab.bitfireAT:dav4jvm
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

app/build.gradle

@@ -191,7 +191,7 @@ dependencies {
     implementation 'androidx.exifinterface:exifinterface:1.3.3'
     androidTestImplementation "androidx.work:work-testing:${workVersion}"
     implementation 'com.google.android:flexbox:2.0.1'
-    implementation ('com.gitlab.bitfireAT:dav4jvm:2.1.2', {
+    implementation ('com.gitlab.bitfireAT:dav4jvm:2.1.3', {
         exclude group: 'org.ogce', module: 'xpp3'	// Android comes with its own XmlPullParser
     })
     ktlint "com.pinterest:ktlint:0.42.1"