Add libjemalloc2-dev as Build-Depends

Author: bigbruno

debian/control

@@ -21,6 +21,7 @@ Build-Depends:
  libgsf-1-dev,
  libgtk-3-dev (>= 3.10),
  libgtk-3-doc,
+ libjemalloc2-dev,
  libjson-glib-dev (>= 1.6),
  libpango1.0-dev,
  libx11-dev,