increment version number to 0.21.3

NEWS

+ver 0.21.3 (not yet released)
+
 ver 0.21.2 (2018/11/12)
 * protocol
   - operator "=~" matches a regular expression

android/AndroidManifest.xml

@@ -2,8 +2,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
           package="org.musicpd"
           android:installLocation="auto"
-          android:versionCode="24"
-          android:versionName="0.21.2">
+          android:versionCode="25"
+          android:versionName="0.21.3">
 
   <uses-sdk android:minSdkVersion="21" android:targetSdkVersion="26"/>
 

doc/conf.py

@@ -38,7 +38,7 @@ author = 'Max Kellermann'
 # built documents.
 #
 # The short X.Y version.
-version = '0.21.2'
+version = '0.21.3'
 # The full version, including alpha/beta/rc tags.
 release = version
 

meson.build

 project(
   'mpd',
   ['c', 'cpp'],
-  version: '0.21.2',
+  version: '0.21.3',
   meson_version: '>= 0.47.2',
   default_options: [
     'c_std=c99',