cmake: always use object library for git2internal

As we have bumped our minimum CMake version to 2.8.11, we can now
unconditionally make use of object libraries. So remove the version
check for the git2internal object library and always use it.

src/CMakeLists.txt

@@ -334,21 +334,16 @@ CONFIGURE_FILE(features.h.in git2/sys/features.h)
 
 SET(LIBGIT2_SOURCES ${SRC_H} ${SRC_GIT2} ${SRC_OS} ${SRC_SSH} ${SRC_SHA1})
 
-IF (CMAKE_VERSION VERSION_GREATER 2.8.7)
-	ADD_LIBRARY(git2internal OBJECT ${LIBGIT2_SOURCES})
-	IDE_SPLIT_SOURCES(git2internal)
-	LIST(APPEND LIBGIT2_OBJECTS $<TARGET_OBJECTS:git2internal>)
+ADD_LIBRARY(git2internal OBJECT ${LIBGIT2_SOURCES})
+IDE_SPLIT_SOURCES(git2internal)
+LIST(APPEND LIBGIT2_OBJECTS $<TARGET_OBJECTS:git2internal>)
 
-	IF (${CMAKE_VERSION} VERSION_LESS 2.8.12)
-		INCLUDE_DIRECTORIES(${LIBGIT2_INCLUDES})
-	ELSE()
-		TARGET_INCLUDE_DIRECTORIES(git2internal
-		    PRIVATE ${LIBGIT2_INCLUDES}
-		    PUBLIC ${CMAKE_SOURCE_DIR}/include)
-	ENDIF()
-ELSE()
+IF (${CMAKE_VERSION} VERSION_LESS 2.8.12)
 	INCLUDE_DIRECTORIES(${LIBGIT2_INCLUDES})
-	LIST(APPEND LIBGIT2_OBJECTS ${LIBGIT2_SOURCES})
+ELSE()
+	TARGET_INCLUDE_DIRECTORIES(git2internal
+	    PRIVATE ${LIBGIT2_INCLUDES}
+	    PUBLIC ${CMAKE_SOURCE_DIR}/include)
 ENDIF()
 
 SET(LIBGIT2_OBJECTS ${LIBGIT2_OBJECTS} PARENT_SCOPE)