- remove flags that make no sense for us
- fix CMake boo-boo (pr#364 on the gmic repo)

Index: CMakeLists.txt
--- CMakeLists.txt.orig
+++ CMakeLists.txt
@@ -102,7 +102,7 @@ if(APPLE)
 elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
     list(APPEND GMIC_CXX_COMPILE_FLAGS -Wno-error=c++11-narrowing -fpermissive)
 else()
-    list(APPEND GMIC_CXX_COMPILE_FLAGS -Wno-error=narrowing -fno-ipa-sra -fpermissive)
+    list(APPEND GMIC_CXX_COMPILE_FLAGS -Wno-error=narrowing -fpermissive)
 endif()
 
 if(NOT "${PRERELEASE_TAG}" STREQUAL "")