tests: use cgienv to minimize environment setup at hgweb tests

This patch follows other hgweb tests.

tests/test-extension.t

@@ -116,9 +116,9 b" Check hgweb's load order of extensions a"
   > application = hgweb('.', 'test repo')
   > wsgicgi.launch(application)
   > EOF
+  $ . "$TESTDIR/cgienv"
 
-  $ REQUEST_METHOD='GET' PATH_INFO='/' SCRIPT_NAME='' QUERY_STRING='' \
-  >    SERVER_PORT='80' SERVER_NAME='localhost' python hgweb.cgi \
+  $ PATH_INFO='/' SCRIPT_NAME='' python hgweb.cgi \
   >    | grep '^[0-9]) ' # ignores HTML output
   1) foo imported
   1) bar imported
@@ -137,9 +137,7 b" Check hgweb's load order of extensions a"
   $ PATH_INFO='/shortlog'
 #endif
   $ export PATH_INFO
-  $ REQUEST_METHOD='GET' SCRIPT_NAME='' \
-  >     QUERY_STRING='rev=foo() and bar()' \
-  >     SERVER_PORT='80' SERVER_NAME='localhost' python hgweb.cgi \
+  $ SCRIPT_NAME='' QUERY_STRING='rev=foo() and bar()' python hgweb.cgi \
   >     | grep '<a href="/rev/[0-9a-z]*">'
      <a href="/rev/c24b9ac61126">add file</a>
 

tests/test-largefiles.t

@@ -222,13 +222,9 b' Test largefiles can be loaded in hgweb ('
   > application = hgweb('.', 'test repo')
   > wsgicgi.launch(application)
   > EOF
+  $ . "$TESTDIR/cgienv"
 
-  $ PATH_INFO='/' \
-  > QUERY_STRING='' \
-  > REQUEST_METHOD='GET' \
-  > SCRIPT_NAME='' \
-  > SERVER_NAME='localhost' \
-  > SERVER_PORT='80' \
+  $ SCRIPT_NAME='' \
   > python "$TESTTMP/hgweb.cgi" > /dev/null
 
 Test archiving the various revisions.  These hit corner cases known with