Fix mythzoneminder on mac part #3

Reverse change done in a513779, only do it on the mac.
Not elegant, but I don't understand qmake's behaviour

mythplugins/mythzoneminder/mythzmserver/mythzmserver.pro

@@ -10,15 +10,17 @@ target.path = $${PREFIX}/bin
 
 INSTALLS = target
 
-MYSQLIBS = "$$system(mysql_config --libs)"
 macx {
     CONFIG += qt
     QT += sql
     #Can't use mysql_config output, as it could have been compiled with
     # universal support, and we may want just 32 or 64 bits
+    MYSQLIBS = "$$system(mysql_config --libs)"
     MYSQLIBS ~= s/-arch +[a-z0-9_]+//g
-}
-LIBS += $$MYSQLIBS
+    LIBS += $$sptrinf($$MYSQLIBS) 
+} else {
+    LIBS += $$system(mysql_config --libs)
+}                                                                              
 
 linux: DEFINES += linux