install_mongocxx: removing "make" commands. if ninja is the default build...

install_mongocxx: removing "make" commands. if ninja is the default build system, this script failed

etc/mongocxx/install_mongocxx.sh

@@ -141,9 +141,8 @@ cd build
 cmake ..
 cmake .. -DBSON_LIBRARY="/usr/lib/x86_64-linux-gnu/libbson-1.0.so" -DMONGOC_LIBRARY="/usr/lib/x86_64-linux-gnu/libmongoc-1.0.so" -DCMAKE_INSTALL_PREFIX="$installDir"
 # install to $extractDir/build/install
-make -j`nproc`
-make install
-
+cmake --build . -- -j`nproc`
+cmake --build . --target install
 
 # Finally, tell RobotAPI where to find mongocxx
 echo "$HIGHLIGHT