Don't look for libhistory.

Apparently libreadline provides this now (maybe it always did?), and it fixes
 things on OpenBSD.
(transplanted from d842cd8c9f9156f24d3776cb9b97f0ae051c88c0)

CMakeLists.txt

@@ -308,13 +308,12 @@ IF(PHYSFS_BUILD_TEST)
         FIND_LIBRARY(CURSES_LIBRARY NAMES curses ncurses)
         SET(CMAKE_REQUIRED_LIBRARIES ${CURSES_LIBRARY})
         FIND_LIBRARY(READLINE_LIBRARY readline)
-        FIND_LIBRARY(HISTORY_LIBRARY history)
-        IF(READLINE_LIBRARY AND HISTORY_LIBRARY)
+        IF(READLINE_LIBRARY)
             SET(HAVE_SYSTEM_READLINE TRUE)
             SET(TEST_PHYSFS_LIBS ${TEST_PHYSFS_LIBS} ${READLINE_LIBRARY} ${CURSES_LIBRARY})
             INCLUDE_DIRECTORIES(${READLINE_H} ${HISTORY_H})
             ADD_DEFINITIONS(-DPHYSFS_HAVE_READLINE=1)
-        ENDIF(READLINE_LIBRARY AND HISTORY_LIBRARY)
+        ENDIF(READLINE_LIBRARY)
     ENDIF(READLINE_H AND HISTORY_H)
     ADD_EXECUTABLE(test_physfs test/test_physfs.c)
     TARGET_LINK_LIBRARIES(test_physfs ${PHYSFS_LIB_TARGET} ${TEST_PHYSFS_LIBS} ${OTHER_LDFLAGS})