Update buildroot to 2021.02.4 (#1522)

Signed-off-by: Stefan Agner <stefan@agner.ch>

buildroot/package/python3/0024-Add-an-option-to-disable-decimal.patch

@@ -22,7 +22,7 @@ diff --git a/configure.ac b/configure.ac
 index 7bd4623ccd..e513ef6a20 100644
 --- a/configure.ac
 +++ b/configure.ac
-@@ -3106,13 +3106,20 @@ fi
+@@ -3135,13 +3135,20 @@ fi
  AC_SUBST(LIBFFI_INCLUDEDIR)
  
  # Check for use of the system libmpdec library
@@ -52,7 +52,7 @@ diff --git a/setup.py b/setup.py
 index c4ee989ba3..3d0c74bb7f 100644
 --- a/setup.py
 +++ b/setup.py
-@@ -2221,7 +2221,7 @@ class PyBuildExt(build_ext):
+@@ -2195,7 +2195,7 @@ class PyBuildExt(build_ext):
          # Stefan Krah's _decimal module
          extra_compile_args = []
          undef_macros = []