Remove a broken YouTube link

Author: JohnTitor

src/mir/dataflow.md

@@ -16,9 +16,7 @@ It is merely a description of the framework used to define these analyses in
 some basic terminology, such as "transfer function", "fixpoint" and "lattice".
 If you're unfamiliar with these terms, or if you want a quick refresher,
 [*Static Program Analysis*] by Anders Møller and Michael I. Schwartzbach is an
-excellent, freely available textbook. For those who prefer audiovisual
-learning, the Goethe University Frankfurt has published a series of short
-[lectures on YouTube][goethe] in English that are very approachable.
+excellent, freely available textbook.
 
 ## Defining a Dataflow Analysis
 
@@ -229,6 +227,5 @@ the example below:
 [`apply_call_return_effect`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_mir_dataflow/trait.Analysis.html#tymethod.apply_call_return_effect
 [`into_engine`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_mir_dataflow/trait.Analysis.html#method.into_engine
 [`lattice`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_mir_dataflow/lattice/index.html
-[goethe]: https://www.youtube.com/watch?v=NVBQSR_HdL0&list=PL_sGR8T76Y58l3Gck3ZwIIHLWEmXrOLV_&index=2
 [lattice]: https://en.wikipedia.org/wiki/Lattice_(order)
 [wiki]: https://en.wikipedia.org/wiki/Data-flow_analysis#Basic_principles