Update SHA tag of MLPCpp module (#2690)

There was a bug in the routine checking the inclusion of the query in the range of the network inputs. When loading multiple networks with the same input and output variables, MLPCpp checks which of the networks has an input range that includes the query. This was done incorrectly, resulting in extrapolation. Now this bug has been fixed in MLPCpp and the submodule tag was updated

Author: EvertBunschoten

meson_scripts/init.py

@@ -74,7 +74,7 @@ def init_submodules(
     github_repo_mel = "https://github.com/pcarruscag/MEL"
     sha_version_fado = "ce7ee018e4e699af5028d69baa1939fea290e18a"
     github_repo_fado = "https://github.com/pcarruscag/FADO"
-    sha_version_mlpcpp = "e19ca0cafb28c4b7ba5b8cffef42883259b00dc0"
+    sha_version_mlpcpp = "ff57e0cf9e60127196d3f1be71e711d47ff646ef"
     github_repo_mlpcpp = "https://github.com/EvertBunschoten/MLPCpp"
     sha_version_eigen = "d71c30c47858effcbd39967097a2d99ee48db464"
     github_repo_eigen = "https://gitlab.com/libeigen/eigen.git"