Update for pacman 4.1, which calls prepare() automatically

PKGBUILD

@@ -8,7 +8,7 @@ pkgver=1.3.1
 _seafilever=1.5.3
 
 #The release number for the arch package, as fixes are added to the PKGBUILD, the release number will increase
-pkgrel=3
+pkgrel=4
 
 # The description of the package, should be about 80 characters long (one line)
 pkgdesc="A framework for writing networked applications in C."
@@ -26,7 +26,7 @@ license=('custom')
 depends=('libzdb>=2.10.2' 'libsearpc>=1.0.1')
 
 # Packages that must be installed to build the software, but at not necessary to run it
-makedepends=('vala>=0.8' 'libmysqlclient')
+makedepends=('vala>=0.8' 'libmysqlclient' 'pacman>=4.1')
 
 # Optional packages that extend the software's functionality
 optdepends=('libmysqlclient')
@@ -50,7 +50,6 @@ prepare () {
 }
 
 build () {
-	prepare
 	cd "$srcdir/seafile-$_seafilever/ccnet"
 	./configure --enable-server --prefix=/usr PYTHON=/usr/bin/python2
 	make -j1