fix typo in GH username

Author: japaric

newsletters/2018-03-29.md

@@ -11,7 +11,7 @@ If you want to mention something in [the next newsletter], make sure to leave a
 
 ## Highlights
 
-* [drbgn] has kicked off an investigation on how to [mock embedded-hal] to make testing sensors easier
+* [dbrgn] has kicked off an investigation on how to [mock embedded-hal] to make testing sensors easier
 * [emilgardis] and [ryankurte] are busy [refactoring] the [svd-parser] crate
 * [japaric], [hannobraun], and [jamesmunns] from the [Embedded WG] attended the 2018 Rust All Hands in Berlin, working on our goal to make [stable embedded rust development] possible in 2018. See the bottom of this post for more details!