[LyX/master] Cmake build: Add qt-svg-lib to be linked with lyx if used QT4.

[Kornel Benko]

commit 050d817605f5033d3937c0f3734cd210a4bb1b64
Author: Kornel Benko <kor...@lyx.org>
Date:   Sun Sep 11 15:34:58 2016 +0200

    Cmake build: Add qt-svg-lib to be linked with lyx if used QT4.
    
    Probably due to commit 82808fe, there were undefined references
    such as e.g. QSvgRenderer::~QSvgRenderer().
---
 src/CMakeLists.txt |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 0c56ce6..b7d1b06 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -132,6 +132,9 @@ target_link_libraries(${_lyx}
        ${LYX_QTMAIN_LIBRARY}
        ${vld_dll})
 
+if(LYX_USE_QT MATCHES "QT4")
+  target_link_libraries(${_lyx} ${QT_QTSVG_LIBRARY})
+endif()
 qt_use_modules(${_lyx} Core Gui)
 
 if(QT_USES_X11)