Avoid configure warning when checking ogre-1.10 (#411)

* Avoid warning on missing components when detecting ogre 1.10

Signed-off-by: Jose Luis Rivero <jrivero@osrfoundation.org>

CMakeLists.txt

@@ -65,13 +65,17 @@ list(APPEND ign_ogre_components "RTShaderSystem" "Terrain" "Overlay")
 # Display a warning for the users on this setup unless they provide
 # USE_UNOFFICAL_OGRE_VERSIONS flag
 if (NOT USE_UNOFFICAL_OGRE_VERSIONS)
-  ign_find_package(IgnOGRE VERSION 1.10
-    COMPONENTS ${ign_ogre_components})
+  # Only for checking the ogre version
+  ign_find_package(IgnOGRE VERSION 1.10 QUIET)
 
   if (OGRE_FOUND)
     IGN_BUILD_WARNING("Ogre 1.x versions greater than 1.9 are not officially supported."
                       "The software might compile and even work but support from upstream"
                       "could be reduced to accepting patches for newer versions")
+    ign_find_package(IgnOGRE VERSION 1.10
+      COMPONENTS ${ign_ogre_components}
+      REQUIRED_BY ogre
+      PRIVATE_FOR ogre)
   else()
     # If ogre 1.10 or greater was not found, then proceed to look for 1.9.x
     # versions which are offically supported