follow the googletest merge in build-depends

debian/control

@@ -16,7 +16,7 @@ Build-Depends: cmake (>= 3.4),
                libbz2-dev,
                libcurl4-gnutls-dev (>= 7.19.4~),
                libdb-dev,
-               libgtest-dev <!nocheck>,
+               googletest <!nocheck> | libgtest-dev <!nocheck>,
                liblz4-dev (>= 0.0~r126),
                liblzma-dev,
                pkg-config,

test/libapt/CMakeLists.txt

@@ -1,5 +1,7 @@
-set(GTEST_ROOT "/usr/src/gtest" CACHE FILEPATH "Path to GTest CMake project")
-
+find_path(GTEST_ROOT src/gtest.cc
+   /usr/src/googletest/googletest
+   /usr/src/gtest
+)
 find_package(GTest)
 set(GTEST_DEPENDENCIES)