[bag_tools] Remove explicit dependency on boost signals

`libboost-signals` does not exist anymore in recent `libboost` versions, and as been replaced by the (mostly) API compatible `libboost-signals2`, distributed with `libboost` (for instance, on Ubuntu 20.04, in the package `libboost1.71-dev`).

Author: severin-lemaignan

bag_tools/CMakeLists.txt

@@ -2,7 +2,7 @@ cmake_minimum_required(VERSION 2.8.3)
 project(bag_tools)
 
 find_package(catkin REQUIRED COMPONENTS rospy rosbag sensor_msgs cv_bridge message_filters image_proc stereo_image_proc image_geometry camera_calibration_parsers)
-find_package(Boost REQUIRED COMPONENTS signals thread)
+find_package(Boost REQUIRED COMPONENTS thread)
 find_package(OpenCV REQUIRED)
 find_package(console_bridge REQUIRED)
 
@@ -63,4 +63,4 @@ install(PROGRAMS
 
 install(DIRECTORY launch/
   DESTINATION ${CATKIN_PACKAGE_SHARE_DESTINATION}/launch
-  PATTERN ".svn" EXCLUDE)
+  PATTERN ".svn" EXCLUDE)