fix flickering of progress bar on package installation (#3993)

(cherry picked from commit a717900)

Author: KristofferC

src/MiniProgressBars.jl

@@ -40,7 +40,7 @@ function show_progress(io::IO, p::MiniProgressBar; termwidth=nothing, carriagere
         return
     end
     t = time()
-    if p.has_shown && (t - p.time_shown) < PROGRESS_BAR_TIME_GRANULARITY[]
+    if !p.always_reprint && p.has_shown && (t - p.time_shown) < PROGRESS_BAR_TIME_GRANULARITY[]
         return
     end
     p.time_shown = t