Deb: Make AWS key management plugin a special plugin not in Linux distros

It will only build if there is network access, which is a strict no-go
for Linux distributions. Thus the AWS plugin needs to be a custom built
only special plugin that is not built as part of the normal sources.

This fixes the build error in e.g. Launchpad:

  Performing download step (git clone) for 'aws_sdk_cpp'
  cd "/<<PKGBUILDDIR>>/builddir/plugin/aws_key_management" && /usr/bin/cmake ..
  Cloning into 'aws-sdk-cpp'...
  fatal: unable to access 'https://github.com/awslabs/aws-sdk-cpp.git/':
  Could not resolve host: github.com

debian/autobake-deb.sh

@@ -86,11 +86,30 @@ then
   sed '/Package: mariadb-plugin-rocksdb/,+14d' -i debian/control
 fi
 
-# AWS SDK requires c++11 -capable compiler
+# AWS SDK requires c++11 -capable compiler.
 # Minimal supported versions are g++ 4.8 and clang 3.3.
-if [[ $GCCVERSION -lt 40800 ]] || [[ $TRAVIS ]]
+# AWS SDK also requires the build machine to have network access and git, so
+# it cannot be part of the base version included in Linux distros, but a pure
+# custom built plugin.
+if [[ $GCCVERSION -gt 40800 ]] && [[ ! $TRAVIS ]] && ping -c 1 github.com
 then
-  sed '/Package: mariadb-plugin-aws-key-management/,+14d' -i debian/control
+  cat <<EOF >> debian/control
+
+Package: mariadb-plugin-aws-key-management
+Architecture: any
+Breaks: mariadb-aws-key-management-10.1,
+        mariadb-aws-key-management-10.2
+Replaces: mariadb-aws-key-management-10.1,
+          mariadb-aws-key-management-10.2
+Depends: libcurl3,
+         mariadb-server-10.3,
+         \${misc:Depends},
+         \${shlibs:Depends}
+Description: Amazon Web Service Key Management Service Plugin for MariaDB
+ This encryption key management plugin gives an interface to the Amazon Web
+ Services Key Management Service for managing encryption keys used for MariaDB
+ data-at-rest encryption.
+EOF
 fi
 
 # Mroonga, TokuDB never built on Travis CI anyway, see build flags above

debian/control

@@ -694,21 +694,6 @@ Description: CrackLib Password Validation Plugin for MariaDB
  This password validation plugin uses cracklib to allow only
  sufficiently secure (as defined by cracklib) user passwords in MariaDB.
 
-Package: mariadb-plugin-aws-key-management
-Architecture: any
-Breaks: mariadb-aws-key-management-10.1,
-        mariadb-aws-key-management-10.2
-Replaces: mariadb-aws-key-management-10.1,
-          mariadb-aws-key-management-10.2
-Depends: libcurl3,
-         mariadb-server-10.3,
-         ${misc:Depends},
-         ${shlibs:Depends}
-Description: Amazon Web Service Key Management Service Plugin for MariaDB
- This encryption key management plugin gives an interface to the Amazon Web
- Services Key Management Service for managing encryption keys used for MariaDB
- data-at-rest encryption.
-
 Package: mariadb-test
 Architecture: any
 Depends: mariadb-client-10.3 (= ${binary:Version}),