kcoreaddons: Fix build with Qt 5.15

%ci:no-build

x11-packages/kcoreaddons/src-lib-randomness-krandom.cpp.patch

@@ -0,0 +1,11 @@
+--- a/src/lib/randomness/krandom.cpp
++++ b/src/lib/randomness/krandom.cpp
+@@ -62,7 +62,7 @@
+         if (r > 90) {
+             r += 6;
+         }
+-        str[i++] =  char(r);
++        str[i++] = QLatin1Char(char(r));
+         // so what if I work backwards?
+     }
+     return str;