Dockerfile: avoid -march=native compiler flag

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@73690 15284696-431f-4ddb-bdfa-cd5b030d7da7

Dockerfile

@@ -77,7 +77,7 @@ COPY . /code/grass
 WORKDIR /code/grass
 
 # Set gcc/g++ environmental variables for GRASS GIS compilation, without debug symbols
-ENV MYCFLAGS "-O2 -march=native -std=gnu99 -m64"
+ENV MYCFLAGS "-O2 -std=gnu99 -m64"
 ENV MYLDFLAGS "-s"
 # CXX stuff:
 ENV LD_LIBRARY_PATH "/usr/local/lib"