Corrected description of --sig-proxy

Signal proxy does work only in non-TTY mode (--tty=false). Man pages and
commands should not lie about it.

Signed-off-by: Michal Minar <miminar@redhat.com>

docs/sources/reference/commandline/cli.md

@@ -227,7 +227,7 @@ Docker supports softlinks for the Docker data directory
     Attach to a running container
 
       --no-stdin=false    Do not attach STDIN
-      --sig-proxy=true    Proxy all received signals to the process (even in non-TTY mode). SIGCHLD, SIGKILL, and SIGSTOP are not proxied.
+      --sig-proxy=true    Proxy all received signals to the process (non-TTY mode only). SIGCHLD, SIGKILL, and SIGSTOP are not proxied.
 
 The `attach` command lets you view or interact with any running container's
 primary process (`pid 1`).
@@ -1243,7 +1243,7 @@ removed before the image is removed.
       --privileged=false         Give extended privileges to this container
       --restart=""               Restart policy to apply when a container exits (no, on-failure[:max-retry], always)
       --rm=false                 Automatically remove the container when it exits (incompatible with -d)
-      --sig-proxy=true           Proxy received signals to the process (even in non-TTY mode). SIGCHLD, SIGSTOP, and SIGKILL are not proxied.
+      --sig-proxy=true           Proxy received signals to the process (non-TTY mode only). SIGCHLD, SIGSTOP, and SIGKILL are not proxied.
       -t, --tty=false            Allocate a pseudo-TTY
       -u, --user=""              Username or UID
       -v, --volume=[]            Bind mount a volume (e.g., from the host: -v /host:/container, from Docker: -v /container)

docs/sources/reference/run.md

@@ -82,7 +82,7 @@ and pass along signals. All of that is configurable:
 
     -a=[]           : Attach to `STDIN`, `STDOUT` and/or `STDERR`
     -t=false        : Allocate a pseudo-tty
-    --sig-proxy=true: Proxify all received signal to the process (even in non-tty mode)
+    --sig-proxy=true: Proxify all received signal to the process (non-TTY mode only)
     -i=false        : Keep STDIN open even if not attached
 
 If you do not specify `-a` then Docker will [attach all standard

docs/sources/userguide/usingdocker.md

@@ -85,7 +85,7 @@ This will display the help text and all available flags:
     Attach to a running container
 
       --no-stdin=false: Do not attach stdin
-      --sig-proxy=true: Proxify all received signal to the process (even in non-tty mode)
+      --sig-proxy=true: Proxify all received signal to the process (non-TTY mode only)
 
 > **Note:** 
 > You can see a full list of Docker's commands