fix for adjoint=false and linking of symbolic_functions.o
fix for adjoint=false and linking of symbolic_functions.o

FFroehlich/AMICI,AMICI-developer/AMICI,AMICI-developer/AMICI,AMICI-developer/AMICI,paulstapor/AMICI,FFroehlich/AMICI,paulstapor/AMICI,paulstapor/AMICI,paulstapor/AMICI,FFroehlich/AMICI,FFroehlich/AMICI,AMICI-developer/AMICI