Fix building with new MCC code

Author: CaptainSwag101

Orbitersdk/samples/ProjectApollo/Project/MCC/CMakeLists.txt

@@ -16,6 +16,7 @@ set(SOURCES
     ${NASSP_SOURCE_ROOT}/src_launch/mcc.cpp
     ${NASSP_SOURCE_ROOT}/src_launch/mccvc.cpp
     ${NASSP_SOURCE_ROOT}/src_launch/mccvessel.cpp
+    ${NASSP_SOURCE_ROOT}/src_launch/MCC_Calculations.cpp
     ${NASSP_SOURCE_ROOT}/src_launch/MCC_Mission_B.cpp
     ${NASSP_SOURCE_ROOT}/src_launch/MCC_Mission_C.cpp
     ${NASSP_SOURCE_ROOT}/src_launch/MCC_Mission_C_PRIME.cpp
@@ -73,4 +74,4 @@ target_link_libraries(${PROJECT_NAME} PRIVATE
     Orbitersdk
     WinMM
     WS2_32
-)
+)