meson.build: Fix warning for configure_file

We claim to support meson versions >= 0.47 but the `install:` argument
in configure_file was introduced in version 0.50. This produces the
following meson warning:

WARNING: Project specifies a minimum meson_version '>= 0.47' but uses
features which were added in newer versions:
 * 0.50.0: {'install arg in configure_file'}

From the documentation for the install argument [1]:
" When omitted it (install) defaults to true when install_dir is set and
not empty, false otherwise."

So, remove the `install:` argument and just depend on `install_dir` for
installing.

Fixes: https://gitlab.freedesktop.org/wayland/weston/issues/225

[1] https://mesonbuild.com/Reference-manual.html#configure_file

Signed-off-by: Harish Krupo <harish.krupo.kps@intel.com>

man/meson.build

@@ -11,7 +11,6 @@ man_conf.set('version', version_weston)
 configure_file(
 	input: 'weston.man',
 	output: 'weston.1',
-	install: true,
 	install_dir: join_paths(dir_man, 'man1'),
 	configuration: man_conf
 )
@@ -19,7 +18,6 @@ configure_file(
 configure_file(
 	input: 'weston-debug.man',
 	output: 'weston-debug.1',
-	install: true,
 	install_dir: join_paths(dir_man, 'man1'),
 	configuration: man_conf
 )
@@ -27,7 +25,6 @@ configure_file(
 configure_file(
 	input: 'weston.ini.man',
 	output: 'weston.ini.5',
-	install: true,
 	install_dir: join_paths(dir_man, 'man5'),
 	configuration: man_conf
 )
@@ -36,7 +33,6 @@ if get_option('backend-drm')
 	configure_file(
 		input: 'weston-drm.man',
 		output: 'weston-drm.7',
-		install: true,
 		install_dir: join_paths(dir_man, 'man7'),
 		configuration: man_conf
 	)
@@ -46,7 +42,6 @@ if get_option('backend-rdp')
 	configure_file(
 		input: 'weston-rdp.man',
 		output: 'weston-rdp.7',
-		install: true,
 		install_dir: join_paths(dir_man, 'man7'),
 		configuration: man_conf
 	)