Backport move to Ubuntu Bionic and GCC7 in Gitian builds (dashpay#2225)

* Add stdin, stdout, stderr to ignored export list

* Merge bitcoin#13171: Change gitian-descriptors to use bionic instead

c1afe32 Change gitian-descriptors to use bionic instead (Chun Kuan Lee)

Pull request description:

  I have tested this with Ubuntu Bionic host with lxc 3.0.0, the gitian-build for Windows and MacOSX work fine, but there is an issue about it for Linux. Failed at check-symbol:
  ```
  test/test_bitcoin: symbol __divmoddi4 from unsupported version GCC_7.0.0
  test/test_bitcoin: symbol log2f from unsupported version GLIBC_2.27
  qt/bitcoin-qt: symbol __divmoddi4 from unsupported version GCC_7.0.0
  qt/bitcoin-qt: symbol log2f from unsupported version GLIBC_2.27
  ```
  I think this should be fixed in `./configure --enable-glibc-back-compat`

  Should not be merged before bitcoin#13177 devrandom/gitian-builder#178

  Close bitcoin#12511

Tree-SHA512: 257d75d5b6864e105279f7a7b992fbbd7903cdbe3300b66dacec0a783d267707d9dbbfe0e64a36983ca1eca50a2a5e1cdb222b6d3745ccc3e5fc5636c88b581f

* Use IN6ADDR_ANY_INIT instead of in6addr_any

This is the same fix as bitcoin@fc6a9f2
Couldn't backport the original commit as we are missing some refactorings.

src/init.cpp

@@ -1457,7 +1457,7 @@ bool AppInit2(boost::thread_group& threadGroup, CScheduler& scheduler)
         else {
             struct in_addr inaddr_any;
             inaddr_any.s_addr = INADDR_ANY;
-            fBound |= Bind(connman, CService(in6addr_any, GetListenPort()), BF_NONE);
+            fBound |= Bind(connman, CService((in6_addr)IN6ADDR_ANY_INIT, GetListenPort()), BF_NONE);
             fBound |= Bind(connman, CService(inaddr_any, GetListenPort()), !fBound ? BF_REPORT_ERROR : BF_NONE);
         }
         if (!fBound)