C#: Set the precision of cs/equality-on-floats to high.

Author: michaelnebel

csharp/ql/src/Likely Bugs/EqualityCheckOnFloats.ql

@@ -5,7 +5,7 @@
  *              computation does not follow the standard rules of algebra.
  * @kind problem
  * @problem.severity warning
- * @precision medium
+ * @precision high
  * @id cs/equality-on-floats
  * @tags reliability
  *       correctness