[PATCH] build: Allow building with GNU Radio master

[argilo at gmail.com]

From: Clayton Smith <argilo at gmail.com>

Currently gr-osmosdr does not build with GNU Radio's master branch,
which declares itself to be version 3.9. This change allows both 3.8
and 3.9.
---
 CMakeLists.txt | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 56c1a6b185..f3186dee0c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -42,7 +42,13 @@ set(CMAKE_BUILD_TYPE ${CMAKE_BUILD_TYPE} CACHE STRING "")
 list(INSERT CMAKE_MODULE_PATH 0 ${CMAKE_SOURCE_DIR}/cmake/Modules)
 
 # Find GNURadio (pmt and runtime are core, always included)
-find_package(Gnuradio "3.8" REQUIRED COMPONENTS blocks fft filter)
+find_package(Gnuradio "3.8" COMPONENTS blocks fft filter)
+if(NOT Gnuradio_FOUND)
+    find_package(Gnuradio "3.9" COMPONENTS blocks fft filter)
+    if(NOT Gnuradio_FOUND)
+        message(FATAL_ERROR "Unable to find GNURadio")
+    ENDIF(NOT Gnuradio_FOUND)
+ENDIF(NOT Gnuradio_FOUND)
 
 # Set the version information here
 set(VERSION_MAJOR 0)
-- 
2.17.1