update deltachat-core-rust submodule to 'move invariant out of loop, less LOC and 1.5% faster'

deltachat-ios/libraries/deltachat-core-rust

@@ -1 +1 @@
-Subproject commit 326a75d0e8226374d9838f981c563e747a59a66e
+Subproject commit 612132b7c89322b3691ac3254c365da688f6dff8