fix NPE in TaskRetrieval#getTextsForSearch

[Alexdoru]

java.lang.RuntimeException: Unexpected exception while checking if quest matched query
    at betterquesting.api2.client.gui.panels.lists.CanvasQuestSearch.queryMatches(CanvasQuestSearch.java:146)
    at betterquesting.api2.client.gui.panels.lists.CanvasQuestSearch.queryMatches(CanvasQuestSearch.java:38)
    at betterquesting.api2.client.gui.panels.lists.CanvasSearch.updateSearch(CanvasSearch.java:74)
    at betterquesting.api2.client.gui.panels.lists.CanvasSearch.drawPanel(CanvasSearch.java:44)
    at betterquesting.api2.client.gui.panels.CanvasEmpty.drawPanel(CanvasEmpty.java:52)
    at betterquesting.api2.client.gui.panels.CanvasEmpty.drawPanel(CanvasEmpty.java:52)
    at betterquesting.api2.client.gui.panels.CanvasTextured.drawPanel(CanvasTextured.java:26)
    at betterquesting.api2.client.gui.GuiScreenCanvas.drawPanel(GuiScreenCanvas.java:271)
    at betterquesting.api2.client.gui.GuiScreenCanvas.drawScreen(GuiScreenCanvas.java:190)
    at net.minecraft.client.renderer.EntityRenderer.updateCameraAndRender(EntityRenderer.java:1061)
    at net.minecraft.client.Minecraft.runGameLoop(Minecraft.java:1001)
    at net.minecraft.client.Minecraft.run(Minecraft.java:7610)
    at net.minecraft.client.main.Main.main(SourceFile:148)
    at jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
    at java.lang.reflect.Method.invoke(Method.java:580)
    at net.minecraft.launchwrapper.Launch.rfb$realLaunch(Launch.java:250)
    at net.minecraft.launchwrapper.Launch.launch(Launch.java:35)
    at net.minecraft.launchwrapper.Launch.main(Launch.java:60)
    at jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
    at java.lang.reflect.Method.invoke(Method.java:580)
    at com.gtnewhorizons.retrofuturabootstrap.Main.main(Main.java:207)
    at com.gtnewhorizons.retrofuturabootstrap.MainStartOnFirstThread.lambda$main$1(MainStartOnFirstThread.java:47)
    at java.lang.Thread.run(Thread.java:1570)
Caused by: java.lang.NullPointerException: Cannot invoke "betterquesting.api.utils.BigItemStack.getBaseStack()" because "bigStack" is null
    at bq_standard.tasks.TaskRetrieval.getTextsForSearch(TaskRetrieval.java:281)
    at betterquesting.api2.client.gui.panels.lists.CanvasQuestSearch.queryMatches(CanvasQuestSearch.java:122)
    ... 22 more

[sisyphussy]

+1 -0