Patch to fix build with jpeg enabled

Issue NGSolve#210
Bug https://bugs.gentoo.org/947728

Signed-off-by: Alexey Shvetsov <[email protected]>

Author: alexxy

CMakeLists.txt

@@ -432,6 +432,9 @@ if (USE_JPEG)
     find_package(JPEG REQUIRED)
     add_definitions(-DJPEGLIB)
     include_directories(${JPEG_INCLUDE_DIR})
+    if(USE_GUI)
+      target_link_libraries(nggui INTERFACE ${JPEG_LIBRARIES})
+    endif(USE_GUI)
 endif (USE_JPEG)
 
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