cmake: enable static linking of OpenSSL if BUILD_STATIC is set

Currently, the BUILD_STATIC and BUILD_STATIC_WITH_BUNDLED_LIBS cmake
options don't enable static linking of the OpenSSL library so we have
to set OPENSSL_USE_STATIC_LIBS explicitly. Let's enable static linking
of OpenSSL by default because we enable it anyway in all our official
builds.

NO_DOC=build
NO_TEST=build
NO_CHANGELOG=build

CMakeLists.txt

@@ -450,6 +450,8 @@ endif()
 # OpenSSL
 #
 
+option(OPENSSL_USE_STATIC_LIBS "Link OpenSSL statically"
+    ${BUILD_STATIC})
 set(ENABLE_BUNDLED_OPENSSL_DEFAULT OFF)
 if(BUILD_STATIC_WITH_BUNDLED_LIBS AND OPENSSL_USE_STATIC_LIBS)
     set(ENABLE_BUNDLED_OPENSSL_DEFAULT ON)
@@ -851,6 +853,7 @@ set(options PACKAGE VERSION BUILD C_COMPILER CXX_COMPILER C_FLAGS CXX_FLAGS
     ENABLE_DOC
     ENABLE_DIST
     ENABLE_BUNDLED_ZLIB
+    OPENSSL_USE_STATIC_LIBS
     ENABLE_BUNDLED_OPENSSL
     ENABLE_BUNDLED_LIBCURL
     BUNDLED_LIBCURL_USE_ARES

static-build/cmake/AddTarantoolProject.cmake

@@ -9,7 +9,6 @@ ExternalProject_Add(tarantool
         # https://cmake.org/cmake/help/v3.4/module/GNUInstallDirs.html#special-cases
         -DCMAKE_INSTALL_LOCALSTATEDIR=<INSTALL_DIR>/var
         -DCMAKE_INSTALL_PREFIX=<INSTALL_DIR>
-        -DOPENSSL_USE_STATIC_LIBS=TRUE
         -DBUILD_STATIC_WITH_BUNDLED_LIBS=TRUE
         -DENABLE_DIST=TRUE
         -DENABLE_HARDENING=${ENABLE_HARDENING}