remove trailing whitespaces

templates/tools/dockerfile/apt_get_basic.include

 # Install Git and basic packages.
 RUN apt-get update && apt-get install -y ${'\\'}
   autoconf ${'\\'}
-  autotools-dev ${'\\'}  
+  autotools-dev ${'\\'}
   build-essential ${'\\'}
   bzip2 ${'\\'}
   ccache ${'\\'}
   curl ${'\\'}
   gcc ${'\\'}
-  gcc-multilib ${'\\'} 
+  gcc-multilib ${'\\'}
   git ${'\\'}
   golang ${'\\'}
   gyp ${'\\'}
@@ -21,7 +21,7 @@ RUN apt-get update && apt-get install -y ${'\\'}
   perl ${'\\'}
   strace ${'\\'}
   python-dev ${'\\'}
-  python-setuptools ${'\\'} 
+  python-setuptools ${'\\'}
   python-yaml ${'\\'}
   telnet ${'\\'}
   unzip ${'\\'}