image-view: remove signals from find_package() calls to support boost 1.69

Deprecated signals library was dropped in 1.69.0 release:
https://www.boost.org/users/history/version_1_69_0.html

Signals (v1) is now removed. Its removal was announced in 1.68 and its
deprecation was announced in 1.54. Boost 1.68 is the last release that
provides this library. Users are encouraged to use Signals2 instead. The
Boost community thanks Douglas Gregor for his work on Signals which
served its users well and which also inspired Signals2.

image-view doesn't use signals at all.

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

recipes-ros/image-pipeline/image-view/image-view-remove-unused-signals-boost-component.patch

@@ -0,0 +1,14 @@
+Upstream-Status: Pending
+
+diff -uNr image_pipeline-1.12.23.orig/image_view/CMakeLists.txt image_pipeline-1.12.23/image_view/CMakeLists.txt
+--- image_pipeline-1.12.23.orig/image_view/CMakeLists.txt       2018-05-10 12:52:54.000000000 +0000
++++ image_pipeline-1.12.23/image_view/CMakeLists.txt    2019-07-03 17:02:21.775288064 +0000
+@@ -5,7 +5,7 @@
+ generate_dynamic_reconfigure_options(cfg/ImageView.cfg)
+
+ catkin_package(CATKIN_DEPENDS dynamic_reconfigure)
+-find_package(Boost REQUIRED COMPONENTS signals thread)
++find_package(Boost REQUIRED COMPONENTS thread)
+ find_package(OpenCV REQUIRED)
+
+ include_directories(${Boost_INCLUDE_DIRS}

recipes-ros/image-pipeline/image-view_1.12.23.bb

@@ -9,3 +9,5 @@ require image-pipeline.inc
 
 inherit distro_features_check
 ANY_OF_DISTRO_FEATURES = "${GTK2DISTROFEATURES}"
+
+SRC_URI += "file://image-view-remove-unused-signals-boost-component.patch;patchdir=.."