runtests: set web.address to localhost

runtests: set web.address to localhost

Previously, "hg serve" will listen on "", which is not clear which interface
it will actually listen on - it could listen on all interfaces (ex. 0.0.0.0
on IPv4).

The run-tests.py script only checks "localhost" for available ports. So
let's make it the same for "hg serve" by explicitly setting "web.address" to
"localhost".

This resolves some IPv6 EADDRINUSE errors.

--- a/tests/run-tests.py	Thu Feb 16 09:38:52 2017 -0800
+++ b/tests/run-tests.py	Thu Feb 16 00:13:29 2017 -0800
@@ -933,6 +933,8 @@
         hgrc.write(b'[largefiles]\n')
         hgrc.write(b'usercache = %s\n' %
                    (os.path.join(self._testtmp, b'.cache/largefiles')))
+        hgrc.write(b'[web]\n')
+        hgrc.write(b'address = localhost\n')
 
         for opt in self._extraconfigopts:
             section, key = opt.split('.', 1)

--- a/tests/test-basic.t	Thu Feb 16 09:38:52 2017 -0800
+++ b/tests/test-basic.t	Thu Feb 16 00:13:29 2017 -0800
@@ -11,6 +11,7 @@
   ui.interactive=False
   ui.mergemarkers=detailed
   ui.promptecho=True
+  web.address=localhost
   web.ipv6=True (?)
   $ hg init t
   $ cd t

--- a/tests/test-commandserver.t	Thu Feb 16 09:38:52 2017 -0800
+++ b/tests/test-commandserver.t	Thu Feb 16 00:13:29 2017 -0800
@@ -199,6 +199,7 @@
   ui.usehttp2=true (?)
   ui.foo=bar
   ui.nontty=true
+  web.address=localhost
   web.ipv6=True (?)
   *** runcommand init foo
   *** runcommand -R foo showconfig ui defaults

--- a/tests/test-http-bundle1.t	Thu Feb 16 09:38:52 2017 -0800
+++ b/tests/test-http-bundle1.t	Thu Feb 16 00:13:29 2017 -0800
@@ -28,11 +28,11 @@
 
 #if windows
   $ hg serve -p $HGPORT1 2>&1
-  abort: cannot start server at ':$HGPORT1': * (glob)
+  abort: cannot start server at 'localhost:$HGPORT1': * (glob)
   [255]
 #else
   $ hg serve -p $HGPORT1 2>&1
-  abort: cannot start server at ':$HGPORT1': Address already in use
+  abort: cannot start server at 'localhost:$HGPORT1': Address already in use
   [255]
 #endif
   $ cd ..

--- a/tests/test-http.t	Thu Feb 16 09:38:52 2017 -0800
+++ b/tests/test-http.t	Thu Feb 16 00:13:29 2017 -0800
@@ -23,7 +23,7 @@
   [255]
 #else
   $ hg serve -p $HGPORT1 2>&1
-  abort: cannot start server at ':$HGPORT1': Address already in use
+  abort: cannot start server at 'localhost:$HGPORT1': Address already in use
   [255]
 #endif
   $ cd ..

--- a/tests/test-https.t	Thu Feb 16 09:38:52 2017 -0800
+++ b/tests/test-https.t	Thu Feb 16 00:13:29 2017 -0800
@@ -36,11 +36,11 @@
 
 #if windows
   $ hg serve -p $HGPORT --certificate=$PRIV 2>&1
-  abort: cannot start server at ':$HGPORT':
+  abort: cannot start server at 'localhost:$HGPORT':
   [255]
 #else
   $ hg serve -p $HGPORT --certificate=$PRIV 2>&1
-  abort: cannot start server at ':$HGPORT': Address already in use
+  abort: cannot start server at 'localhost:$HGPORT': Address already in use
   [255]
 #endif
   $ cd ..