[d17-2] [mono] Bump mono to the latest version of 2020-02 (#15050)

New commits in mono/mono:

* mono/mono@dffa5ab9224 [2020-02] Bump corefx to get MaxResponseHeadersLength fix

Diff: https://github.com/mono/mono/compare/281ee19b9bea648839c2c2256aa88d44d62407d2..dffa5ab92245f2419238a35b7c2052e9a24036b4


Backport of #15042

Co-authored-by: Alex Soto <[email protected]>

Author: vs-mobiletools-engineering-service2

Make.config

@@ -155,9 +155,9 @@ include $(TOP)/mk/mono.mk
 MONO_HASH := $(NEEDED_MONO_VERSION)
 
 # Minimum Mono version for building XI/XM
-MIN_MONO_VERSION=6.12.0.174
+MIN_MONO_VERSION=6.12.0.179
 MAX_MONO_VERSION=6.12.99
-MIN_MONO_URL=https://xamjenkinsartifact.azureedge.net/build-package-osx-mono/2020-02/180/adf1bc4335d710088c58e824b6027255096cc295/MonoFramework-MDK-6.12.0.174.macos10.xamarin.universal.pkg
+MIN_MONO_URL=https://xamjenkinsartifact.azureedge.net/build-package-osx-mono/2020-02/185/dffa5ab92245f2419238a35b7c2052e9a24036b4/MonoFramework-MDK-6.12.0.179.macos10.xamarin.universal.pkg
 
 # Minimum Mono version for Xamarin.Mac apps using the system mono
 MIN_XM_MONO_VERSION=6.4.0.94

mk/mono.mk

@@ -1,4 +1,4 @@
-NEEDED_MONO_VERSION := 281ee19b9bea648839c2c2256aa88d44d62407d2
+NEEDED_MONO_VERSION := dffa5ab92245f2419238a35b7c2052e9a24036b4
 NEEDED_MONO_BRANCH := 2020-02
 
 MONO_DIRECTORY := mono