Fix set_target_properties wrong number of arguments error

CMakeLists.txt

@@ -161,10 +161,10 @@ if (USE_GNUTLS)
 	if(NOT TARGET GnuTLS::GnuTLS)
 		add_library(GnuTLS::GnuTLS UNKNOWN IMPORTED)
 		set_target_properties(GnuTLS::GnuTLS PROPERTIES
-			INTERFACE_INCLUDE_DIRECTORIES ${GNUTLS_INCLUDE_DIRS}
-			INTERFACE_COMPILE_DEFINITIONS ${GNUTLS_DEFINITIONS}
+			INTERFACE_INCLUDE_DIRECTORIES "${GNUTLS_INCLUDE_DIRS}"
+			INTERFACE_COMPILE_DEFINITIONS "${GNUTLS_DEFINITIONS}"
 			IMPORTED_LINK_INTERFACE_LANGUAGES C
-			IMPORTED_LOCATION ${GNUTLS_LIBRARIES})
+			IMPORTED_LOCATION "${GNUTLS_LIBRARIES}")
 	endif()
 	target_compile_definitions(datachannel PRIVATE USE_GNUTLS=1)
 	target_compile_definitions(datachannel-static PRIVATE USE_GNUTLS=1)