fix compiling error when CC_ENABLE_CHIPMUNK_INTEGRATION and CC_ENABLE_BOX2D_INTEGRATION are zero.
add a blank line at the file end.
fix wrong judgments of conditional compilation.
Merge pull request #5045 from Dhilan007/develop_crash

closed #3676: fix compiling error when CC_ENABLE_CHIPMUNK_INTEGRATION and CC_ENABLE_BOX2D_INTEGRATION are zero.