Rebuild .desktop and metainfo when needed

If the translations change then these files need to be regenerated as
they include data from those.

vncviewer/CMakeLists.txt

@@ -79,6 +79,7 @@ if(UNIX)
                 --desktop --template vncviewer.desktop.in
                 -d ${CMAKE_SOURCE_DIR}/po -o vncviewer.desktop
       DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/vncviewer.desktop.in
+              ${CMAKE_SOURCE_DIR}/po/*.po
     )
   elseif(INTLTOOL_MERGE_EXECUTABLE)
     add_custom_command(OUTPUT vncviewer.desktop
@@ -90,6 +91,7 @@ if(UNIX)
                 -d ${CMAKE_SOURCE_DIR}/po
                 vncviewer.desktop.intl vncviewer.desktop
       DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/vncviewer.desktop.in
+              ${CMAKE_SOURCE_DIR}/po/*.po
     )
   else()
     add_custom_command(OUTPUT vncviewer.desktop
@@ -106,6 +108,7 @@ if(UNIX)
                 --xml --template ${CMAKE_CURRENT_SOURCE_DIR}/org.tigervnc.vncviewer.metainfo.xml.in
                 -d ${CMAKE_SOURCE_DIR}/po -o org.tigervnc.vncviewer.metainfo.xml
       DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/org.tigervnc.vncviewer.metainfo.xml.in
+              ${CMAKE_SOURCE_DIR}/po/*.po
     )
   elseif(INTLTOOL_MERGE_EXECUTABLE)
     add_custom_command(OUTPUT org.tigervnc.vncviewer.metainfo.xml
@@ -118,6 +121,7 @@ if(UNIX)
                 -x ${CMAKE_SOURCE_DIR}/po
                 org.tigervnc.vncviewer.metainfo.xml.intl org.tigervnc.vncviewer.metainfo.xml
       DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/org.tigervnc.vncviewer.metainfo.xml.in
+              ${CMAKE_SOURCE_DIR}/po/*.po
     )
   else()
     add_custom_command(OUTPUT org.tigervnc.vncviewer.metainfo.xml