Merge pull request libgit2#4829 from pks-t/pks/cmake-cmp0054

cmake: enable new quoted argument policy CMP0054

Author: ethomson

CMakeLists.txt

@@ -14,12 +14,15 @@
 PROJECT(libgit2 C)
 CMAKE_MINIMUM_REQUIRED(VERSION 2.8.11)
 CMAKE_POLICY(SET CMP0015 NEW)
-IF (POLICY CMP0051)
+IF(POLICY CMP0051)
 	CMAKE_POLICY(SET CMP0051 NEW)
 ENDIF()
-IF (POLICY CMP0042)
+IF(POLICY CMP0042)
 	CMAKE_POLICY(SET CMP0042 NEW)
 ENDIF()
+IF(POLICY CMP0054)
+	CMAKE_POLICY(SET CMP0054 NEW)
+ENDIF()
 
 # Add find modules to the path
 SET(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${libgit2_SOURCE_DIR}/cmake/Modules/")