sophia: build static library only

cmake/BuildSophia.cmake

@@ -6,7 +6,7 @@ macro(sophia_build)
     if (${PROJECT_BINARY_DIR} STREQUAL ${PROJECT_SOURCE_DIR})
 		add_custom_command(OUTPUT ${PROJECT_SOURCE_DIR}/third_party/sophia/db/libsophia.a
 			WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}/third_party/sophia
-			COMMAND $(MAKE) -C db
+			COMMAND $(MAKE) -C db libsophia.a
 			DEPENDS ${CMAKE_SOURCE_DIR}/CMakeCache.txt
 		)
     else()
@@ -16,7 +16,7 @@ macro(sophia_build)
 		add_custom_command(OUTPUT ${PROJECT_BINARY_DIR}/third_party/sophia/db/libsophia.a
 			WORKING_DIRECTORY ${PROJECT_BINARY_DIR}/third_party/sophia
             COMMAND ${CMAKE_COMMAND} -E copy_directory ${PROJECT_SOURCE_DIR}/third_party/sophia ${PROJECT_BINARY_DIR}/third_party/sophia
-			COMMAND $(MAKE) -C db
+			COMMAND $(MAKE) -C db libsophia.a
             DEPENDS ${PROJECT_BINARY_DIR}/CMakeCache.txt ${PROJECT_BINARY_DIR}/third_party/sophia
 		)
     endif()