Fix Brutus C/C++ linking error

Author: LourensVeen

src/amuse/community/brutus/interface.cc

@@ -43,8 +43,6 @@ std::vector<mpreal> data, data_radius;
 // Amuse interface functions
 ////////////////////////////////////////////////////////
 
-extern "C" {
-
 int initialize_code() {
     odata.open("temp.log");
 
@@ -679,5 +677,3 @@ int get_center_of_mass_velocity(double* vx, double* vy, double* vz){
 int get_acceleration(int id, double* ax, double* ay, double* az){return -2;}
 int set_acceleration(int id, double ax, double ay, double az){return -2;}
 
-}       // extern "C"
-