tests: unittests: Fix linking errors.

The linker would throw errors starting with GCC 10 (see:
https://gcc.gnu.org/gcc-10/porting_to.html).  Final fix for
<#882>.

* tests/unittests/account_unittest.cpp (globalEnv): Remove variable.
* tests/unittests/contact_unittest.cpp: Likewise.

Change-Id: I08cff055590c06afb9423759ff3e2c6c6c790e94

tests/unittests/account_unittest.cpp

@@ -19,8 +19,6 @@
 
 #include "globaltestenvironment.h"
 
-TestEnvironment globalEnv;
-
 /*!
  * Test fixture for AccountAdapter testing
  */

tests/unittests/contact_unittest.cpp

@@ -18,8 +18,6 @@
 
 #include "globaltestenvironment.h"
 
-TestEnvironment globalEnv;
-
 /*!
  * Test fixture for AccountAdapter testing
  */