Very minor whitespace corrections.

Author: gwynne

swift-ci/master/debian/10/Dockerfile

@@ -30,7 +30,7 @@ RUN apt-get -y update && apt-get -y --no-install-recommends install \
   systemtap-sdt-dev     \
   tzdata                \
   unzip                 \
-  uuid-dev		\
+  uuid-dev              \
   ca-certificates
 
 USER build-user

swift-ci/master/debian/9/Dockerfile

@@ -28,9 +28,9 @@ RUN apt-get --no-install-recommends -y install \
   systemtap-sdt-dev     \
   tzdata                \
   unzip                 \
-  ca-certificates	\
+  ca-certificates       \
   uuid-dev
 
 USER build-user
 
-WORKDIR /home/build-user
+WORKDIR /home/build-user