chore: bump server version to 29.0.0.4 to trigger migrations

Signed-off-by: Grigorii K. Shartsev <me@shgk.me>

version.php

@@ -30,7 +30,7 @@
 // between betas, final and RCs. This is _not_ the public version number. Reset minor/patch level
 // when updating major/minor version number.
 
-$OC_Version = [29, 0, 0, 3];
+$OC_Version = [29, 0, 0, 4];
 
 // The human-readable string
 $OC_VersionString = '29.0.0 dev';