Prepare 3.21.4

NEWS

+Overview of changes in 3.21.4
+=============================
+
+* Bugs fixed:
+ 756431 identity: Don't leak the invocation when handling SignIn
+ 764157 Port to GTask from GSimpleAsyncResult
+ 766733 kerberos, telepathy: Stopping goa-daemon removes account or expires
+        credentials
+ 767914 Offer a simple mechanism to introspect the available providers and
+        services
+ 768808 identity: Clean up the credential cache and don't keep trying to sign
+        in if we encounter a failure
+ 768845 kerberos: Don't leak the GSimpleAsyncResult and object_path when
+        signing in
+
+* Updated translations:
+ Indonesian
+ Polish
+ Slovak
+ Vietnamese
+
+
 Overview of changes in 3.21.3
 =============================
 

configure.ac

 m4_define([goa_major_version], [3])
 m4_define([goa_minor_version], [21])
-m4_define([goa_micro_version], [3])
+m4_define([goa_micro_version], [4])
 m4_define([goa_nano_version], [0])
 
 m4_define([goa_base_version],