temp/plasma-phone-components: upgrade to 5.19.4_git20200728

Note that this doesn't actually increase the version of the source
files, it's just a bump to be newer than the Alpine packages again

temp/plasma-phone-components/APKBUILD

 # Forked from Alpine to package newer commits
 pkgname=plasma-phone-components
-pkgver=5.19.3_git20200626
+pkgver=5.19.4_git20200626
 pkgrel=0
 _commit="d76fc145f924e06353e38defb088b4e9b32e0e52"
 pkgdesc="Modules providing phone functionality for Plasma"